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Quantum Computing Using Traditional Transistors

Ocean Consulting writes "UCLA is reporting progress on the quantum computing front by announcing success in controlling the spin of a single electron using an ordinary transistor." It's been a long road for the researchers involved, and even the project lead, Hong Wen Jiang admits, "...our initial theoretical calculations were very favorable, and gave us confidence to persevere."

323 comments

  1. Awesome! by erick99 · · Score: 3, Interesting
    Once they get the cost down for actually reading the the state of an electron this will be awesome. Imagine only needing 100 transistors to:

    "With 100 transistors, each containing one of these electrons, you could have the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around," Yablonovitch said. "And why stop with 100 transistors?"

    That is pretty amazing.

    Cheers!

    Erick

    --
    http://www.busyweather.com/
    1. Re:Awesome! by FooAtWFU · · Score: 1

      I don't know... what does "implicit information storage" refer to? How am I supposed to take its... err, implicitness? Most of the time, I want my data to be pretty darned explicit, thank you very much. How much explicit storage (think: how many gigs of, erm, valuable research data ;) could you get off of these?

      --
      The World Wide Web is dying. Soon, we shall have only the Internet.
    2. Re:Awesome! by Sgs-Cruz · · Score: 2, Interesting
      It has to do with all the possible quantum states of the system. I.e. if each transistor has two states, there's 2^100 quantum states of the system when the system contains 100 transistors.

      Actually making use of those squillions of quantum states is something else entirely. It's not like you can just store that much information in 100 transistors, it's that it contains all possible combinations of those 2^100 quantum states while it's running.

      --

      Karma: pi (Mostly due to circular reasoning in posts).

    3. Re:Awesome! by godIsaDJ · · Score: 1
      Gosh, I hate this... Flashy headlines to get attention and research money!

      No, we are not gonna get that kind of hdd, there is simply no way. The problems of coherence and interference make that impossible. Quantum communication it already very difficult uses all sort of error correcting codes to even be theoretically possible.

      Let's put it that way, some king of information is there, there is virtually no way to put your information there and keep it for more that a few nanoseconds :(

    4. Re:Awesome! by Anonymous Coward · · Score: 0

      a 32bit integer contains all possible combinations of 2^32 states. we don't call it the implicit storage of everything, it's simply called 32bits of storage.

    5. Re:Awesome! by base_chakra · · Score: 1

      Yeah, may I be one of the first to say "YEEEEEHAWWW!"

      Quantum computing in general is one of the most exciting technological developments ever. I love reading about progress in this field.

    6. Re:Awesome! by tool462 · · Score: 1

      But a 32 bit integer can only be in one state at a time. For a 32 qubit integer, in can be in all 2^32 states at once.

    7. Re:Awesome! by argent · · Score: 2, Insightful

      Don't be too impressed... it doesn't mean as much as it sounds.

      It's kind of like saying a room full of monkeys implicitly encode all the works of Shakespeare.

    8. Re:Awesome! by Anonymous Coward · · Score: 0

      wow...quite the pessimist

    9. Re:Awesome! by godIsaDJ · · Score: 0

      I'd rather like to consider myself a realist :)

    10. Re:Awesome! by Tongo · · Score: 1

      Pessimists have it better anyways. Those poor optimists are dissappointed half the time, while us pessimists are pleasently suprised half the time.

    11. Re:Awesome! by bugmenot · · Score: 1

      How many Libraries of Congress (LOC) is that?

      --
      This account has been seized by the GNAA. That is all.
    12. Re:Awesome! by Theaetetus · · Score: 1
      It's kind of like saying a room full of monkeys implicitly encode all the works of Shakespeare.

      Yes, and no... Classically, no, but if they were quantum monkeys...

      The point of quantum computing is that each electron can simultaneously have two spin states - used as a 0 and 1 - and can therefore be both a 0 and 1 simultaneously. 3 qubits - (|)(|)(|), being both 0 and 1, encode 8 states, 000, 001, 010, 011, 100, 101, 110, and 111... all at the same time.

      So, a roomful of quantum monkeys, each of whom presses every key simultaneously (and we're talking quantum simultaneously, not just jamming the keys), would be equivalent to all the works of Shakespeare (as long as you have enough monkeys).

      -T

    13. Re:Awesome! by gfody · · Score: 1

      being in all states at once is no better than being in one state at a time. you still need to know which state is important. unless every state is important than what use is the result?

      --

      bite my glorious golden ass.
    14. Re:Awesome! by SparafucileMan · · Score: 1

      So it has (2^100)! bits of info?

    15. Re:Awesome! by Anonymous Coward · · Score: 0

      So how do sort it? How do you find the one set which contains the works of Shakespeare from the billions of other sets which contain garbage?

    16. Re:Awesome! by HermanAB · · Score: 1

      They should compress the data down to 1 bit.

      --
      Oh well, what the hell...
    17. Re:Awesome! by hajihill · · Score: 1

      The above poster is correct, and in fact even reading the stored data will corrupt it by the very nature of the action... it comes back to Schrodinger's Cat in concept...

      Read this for a complete picture... In fact read it several times, it's very confusing... I had to read it like three times...

      On the other hand I suppose this means the NSA will have a leg-up on reading our encrypted data for less, as if that's a good thing. :-/

      --
      Of blankness, I know nothing.
    18. Re:Awesome! by Scorillo47 · · Score: 1

      It is actually better for a different reason. Each of these states evolves in parallel according to the Schrodinger equation for that particular quantum system. In other words you have some sort of parallelism.

      --
      Don't try to use the force. Do or do not, there is no try.
    19. Re:Awesome! by WoodenRobot · · Score: 1
      Most of the time, I want my data to be pretty darned explicit, thank you very much.

      Is prOn all you Slashdotters ever think of?

      ;)

      --
      ---
      "I did nothing. I did absolutely nothing and it was everything that I thought it could be."
    20. Re:Awesome! by joper90 · · Score: 1

      Cool.. a quantum monkey. suddenly life has got better..

    21. Re:Awesome! by GuyWithLag · · Score: 1

      So, does that make you an optimist or a pessimist?

    22. Re:Awesome! by essreenim · · Score: 1

      Quantum computing, which holds the promise of nearly unlimited processing power
      False, but we are talking immense computing power nonetheless. , secure communications
      True and the ability to decode encrypted conversations by terrorists and others
      False. This will only encourage terrorists to increase the number of bits used, and possibly an aternative algorithm. Though it may still be broken, it would take too long, rendering the act of breaking the encryption meaningless.
      The actual real use of this in encryption is that you could instantly know if your encryption was compromised. So if terrorist get it up and running they could know if someone is on to them..

    23. Re:Awesome! by argent · · Score: 1

      Your roomful of quantum monkeys wouldn't be able to hand you a copy of Shakespeare. Your 100 qbits won't be able to hand you any specific disk-drive worth of data that you actually need.

    24. Re:Awesome! by Orca11 · · Score: 1

      Nice theory. I'll wait for Western Digital to tell me I can really have it.

    25. Re:Awesome! by reversible+physicist · · Score: 1
      Exactly the right question! With 100 electron spins you can store the first 100 bits of the library of congress. No more.

      There may be some extra computations you could do with quantum bits, but there are only 2^100 distinct states ("mutually orthogonal states" in QM-speak). That means that if you want to be able to get the data back out, you can only store 100 bits.

    26. Re:Awesome! by argent · · Score: 1

      You have to write a quantum computer program that is only coherent if it happens to generate a valid copy of the works of Shakespeare. Run it on your quantum processor. If at the end of the run the system is still coherent then you have a valid copy of said work.

    27. Re:Awesome! by CreatorOfSmallTruths · · Score: 1

      Well..
      This is wrong in so many levels :)

      Having quantom computing will have lots of possible applications, but most importantly if the "bad guys" will have it , they will be able to create keys much harder to decode than simple RSA stuff...

      The algorithms are already out there. The only thin we should hope for is that DARPA will have some answers for those kind of encryption when quantom computing will be available to mass markets.

      So, no - its not false, you were answering this guy like you know something, but you don't - read up a bit about quantom cryptography and wisen up.

      Btw, I think you were talking about using optical cryptography in your last sentence.. an idea in which you can *measure* the quantom state of the photons you receive during the key swapping and so when the actual message gets you can check if anyone is listening to you.

  2. Secure communications? by agm · · Score: 5, Insightful

    Quantum computing, which holds the promise of nearly unlimited processing power, secure communications and the ability to decode encrypted conversations by terrorists and others, is a significant step closer to becoming a reality today with new research published by a team of UCLA scientists in the journal Nature.

    So which is it, secure communications or communications that can be spied on? It can't be both.

    1. Re:Secure communications? by erick99 · · Score: 1
      I had the same thought when I read that passage. The only thing that comes to mind is some form of secure communication that does not rely on or solely rely on encryption. And if that is the case, I wish the article had more detail because that would be very interesting.

      Cheers!

      Erick

      --
      http://www.busyweather.com/
    2. Re:Secure communications? by Anonymous Coward · · Score: 0

      Basically, it gives you fast decryption and notification of anyone spying on you.

    3. Re:Secure communications? by Anonymous Coward · · Score: 0

      No, i'm pretty sure it can. If there's a way your privacy and human rights can be violated in yet another way - the American Government will be there to adopt the technology and shaft you.

    4. Re:Secure communications? by wmspringer · · Score: 1

      Maybe it assumes that "we" have quantum computers and the bad guys don't?

    5. Re:Secure communications? by repvik · · Score: 1

      Secure communication and the ability to decode "ancient" encryption technologies :)

    6. Re:Secure communications? by maddmike · · Score: 1

      what is probably missing is and the ability to decode non-quantum encrypted conversations...

    7. Re:Secure communications? by tool462 · · Score: 1

      I'm pretty sure they're operating under the assumption that the terrorists don't have quantum computing. It would be easy for quantum computer to decrypt any encryption we have today because of quantum computing's unparalleled ability for parallel processing (pun intended).

      At the same time, quantum encryption (via the very nature of quantum mechanics) would be pretty much unbreakable, since any attempt to capture the data would destroy it.

    8. Re:Secure communications? by Auxon · · Score: 1

      They are assuming that the enemy would not have quantum computing to perform the encryption/decryption, and that the US would.

      This assumption implies that the only people that will be "allowed" to have quantum computers will be the non-terrorists - which means everyone else but the US government, since only "terrorists" would want to do something like encrypt messages that are 100% secure.

      I think the biggest roadblock to quantum computing will be getting over this security hurdle, rather than any technological hurdles.

    9. Re:Secure communications? by RidiculousPie · · Score: 3, Informative

      Most encryption algorithms rely on it being easier to multiply numbers than to factorise them. Quantum computers can easily factorise a large number into a product of primes.

      This is how quantum computers can break encryption

      I'm not sure what they mean by the encryption that is secure though; Quantum encrytion as such is completely separate from Quantum computers, it is just a clever method using detection of the polarisation of light.

      The sending computer begins by sending photons in one of four configuations, two each for the x shape and + shape

      The detectors can only tell the difference between the two states if they are detecting using the correct shape.

      The reciever then transmits a list saying which detector shape it used for each bit, and the sender sends back information saying when it was a correct guess, thus establishing a cipher key

      Now, if someone is intercepting the signal, they will not guess the same way as the reciever, thus they wont have the cipher key at the end (I can't remember if they are detectable becuase they screw with the polarisation or not).

      Thus unbreakable crytography.

      [Disclaimer: IANAPhysicist, and I know that because I read The Code Book by Simon Singh. He describes it properly and accurately (both secure cryptography and breaking today's algorithms with quantum computers)]

      --
      ah, mod points ... now where is my crack?
    10. Re:Secure communications? by lenhap · · Score: 4, Informative

      It is secure and it allows encrypted communications to be spied on. What they don't tell you is that the encrypted comunications are encrypted using standard encryption methods around today. Things that can be cracked by exhaustive search.

      Using a quantum computer it can search every possible key simultaneously, cracking the encryption almost instantly. An example to understand this, you are in a building searching for your briefcase. Normal computers would go through every room one by one until they find it. A quantum computer would find the briefcase by existing in every room at the same time, finally settling (existance wise) in the room with the briefcase.

      They also mention quantum cryptography being uncrackable, this is true. If someone eaves drops on communication that is encrypted, it inherently destroys the data. The users will recognize intrusion and the eavesdropper cannot decrypt the message because the data has been destroyed.

      So yes, quantum computers can decrypt normal encryption that can be broken by exhaustive search and they can be used to provide quantum cryptograph which is a theoretically unbreakable form of communication.

    11. Re:Secure communications? by BrokenStructure · · Score: 1

      It can hack into anything that's not quantum and it can stop anything that's not quantum from hacking into it.

      I wonder what happens if you try to hack a quantum-encoded transmission using a quantum decoder?

      Quantum computers have unlimited processing power. I wouldn't be surprised if quantum technology was solely responsible for altering the way mankind perceives the world.

    12. Re:Secure communications? by Anonymous Coward · · Score: 1, Informative

      They're talking about communications where if someone is snooping on the conversation you will know it. This is done using entanglement. Here's a real world example:

      http://www.newscientist.com/news/news.jsp?id=ns999 94914

      I believe people are already doing this with fiber optics. You can detect very accurately if someone is tapping a fiber optic channel.

    13. Re:Secure communications? by cephyn · · Score: 5, Interesting

      Here's what i never understood, maybe you or someone can help me out...

      if eavesdropping on the encrypted transmission destroys it, couldnt the eavesdropper do so on purpose everytime, effectively jamming all transmission? Little point in having a secure way to communicate if no message can ever get through.

      --
      Moo.
    14. Re:Secure communications? by Jim+Starx · · Score: 1

      Eavesdropping can't possibly destroy the information in every case. The recieving unit has to be able to recieve the information so their must be some way to decode it (would be a pretty useless system if their wasn't, lol). If there is some way to decode it then I have a hard time believing that it is unbreakable.

      --
      The darkness... controls the music. The music... controls the soul.
    15. Re:Secure communications? by Anonymous Coward · · Score: 0
      > Using a quantum computer it can search every possible key simultaneously, cracking the encryption almost instantly. An example to understand this, you are in a building searching for your briefcase. Normal computers would go through every room one by one until they find it. A quantum computer would find the briefcase by existing in every room at the same time, finally settling (existance wise) in the room with the briefcase.

      This is nonsense, perpetuated by people who don't understand quantum mechanics. E.g., Michael Crichton in Timeline. It's really very simple; take a a week off watching Jeopardy to read Preskill's lecture notes: here .

      If you don't have the time for that.. Quantum computing allows a square root speedup and no more in unstructured search. (Searching a key space is generally unstructured. Algebraic problems like factorization have structure.) So say your key is 128 bits. It takes ~2^128 time to search over all the keys classically, and ~2^64 time quantumly. So ~doubling key lengths basically restores security.

    16. Re:Secure communications? by Anonymous Coward · · Score: 0

      Unless the terrorists encrypt it twice. Then you won't know which plaintext is the right one to attempt to decrypt a second time. Which means each re-encryption essentially squares the keyspace. Ouch.

      While this method isn't "cryptographically secure", because knowing how many times to decrypt re-trivializes the problem, it's still going to be plenty effective in the real world.

      It's not hard for two terrorists cells to encrypt their tiny messages somthing like 4,238 times. Good luck, quantum cryptanalysis... wouldn't wanna' be ya'. Not to mention you have to have complete knowledge of what the keyspace is to make a direct attack. If each stage uses RSA 128 bit except for the 384th stage, which uses a simple 4-count alphabet offset, then the quantum system will run right past it and, in the end, find no plaintexts. Do you really want to run automated crypanalysis on every ciphertext of a keyspace that is the keyspace of a 128 bit key to the 4,238th power?

      What all of this means is that, if you really want to keep a secret, it's not going to get much harder. Like armor (vs. arms), cryptanalysis has never really had the lead over cryptography, and it never will.

    17. Re:Secure communications? by Anonymous Coward · · Score: 0

      "Eavesdropping can't possibly destroy the information in every case."

      I don't know much, but I believe the claim of quantum physics is that it will. Every time. That is what the security is based on.

      It may be that it doesn't destroy it, but that eavesdropping is always detectable. If that's the case then you can securely transmit any size of key any time you want, simply be discarding all bits that were spied out. The bits you are left with make a known-secure key. This would allow you to one-time-pad every communication that you sent across a regular network, which would be unbreakable. This would basically just be solving the traditional OTP achielles (sp?) heel.

    18. Re:Secure communications? by Omegalomaniac · · Score: 1

      As far as I know, only asymmetric (public key) cryptography would be completely destroyed. The gains a quantum computer would provide for breaking symmetric cryptography are substantial, but could be defeated by increasing the key length.

    19. Re:Secure communications? by Bingo+Foo · · Score: 2, Informative

      Yes, quantum communication is not magically DOS proof.

      --
      taken! (by Davidleeroth) Thanks Bingo Foo!
    20. Re:Secure communications? by Bingo+Foo · · Score: 2, Informative

      The quantum channel is only used for creating one-time pads (OTP). The channel is eavesdrop-sensitive so you know which bits are compromised and you don't use them in the OTP. Then when you have generated a large enough shared OTP, you use it to encrypt the message and simply send that over regular channels, and since no one else has your securely generated OTP, that message is unbreakable.

      --
      taken! (by Davidleeroth) Thanks Bingo Foo!
    21. Re:Secure communications? by FlynnBoy · · Score: 1

      Once the quantum computer has all possible keys for an encrypted item, how does it know which is the *right* one? I mean, I can understand it comparing results to a dictionary in the case of a text-based item, but what about say an image? How does it weed out the false positives?

    22. Re:Secure communications? by x0n · · Score: 1
      It is secure and it allows encrypted communications to be spied on. What they don't tell you is that the encrypted comunications are encrypted using standard encryption methods around today. Things that can be cracked by exhaustive search.

      Not strictly true in all senses: some implementations use quantum effects to share a string of truely random -- not pseudo-random -- bits which are then used in a one-time pad. If someone eavesdrops on the exchange, it can be detected, and the message aborted (or changed to something misleading or untrue, to either put the listener "off the scent" or reveal the "mole" per-se).

      - Oisin

      --

      PGP KeyId: 0x08D63965
    23. Re:Secure communications? by x0n · · Score: 1

      Duh -- ignore the last bit about fake messages; if it's eavesdropped, there is no way to continue the message enciphering, unless the eavesdropper isn't aware that this is a Q.C. exchange, which is impossible. Shit, this stuff has me confused too and I read about it all the time. :/

      - Oisin

      --

      PGP KeyId: 0x08D63965
    24. Re:Secure communications? by Quixotic137 · · Score: 1

      True, but if you were going to send your credit card info online and you knew that it would be intercepted, you wouldn't send it anyway. You're getting exactly what they say: assured security, not necessarily assured communication.

    25. Re:Secure communications? by Bingo+Foo · · Score: 1
      Disclaimer: IANAPhysicist, and I know that because I read The Code Book by Simon Singh.

      What?

      Let me see...

      Oh, here it is, The Code Book by Simon Singh, page 244: "RidiculousPie is not a physicist."

      Must have been kind of weird to find that out in such a way.

      --
      taken! (by Davidleeroth) Thanks Bingo Foo!
    26. Re:Secure communications? by Rich0 · · Score: 1

      Evesdropping will change the packets as they are enroute. This will cause a measured error rate to go up significantly, which will reveal the evesdropping.

      Google for sites that explain the whole process. It does in fact work.

      Basically, you transmit a one-time-pad over the encrypted link. If it was unintercepted, then you use the pad to encrypt your data, send that over normal communication routes, and decrypt that at the other end. A one-time-pad is of course unbreakable.

      If the pad was intercepted over the quantum-encrypted link, then you just throw it out. Since you never actually used it, the pad does the attacker no good - obviously you'll make a new one the next time you try...

    27. Re:Secure communications? by Christopher+Thomas · · Score: 2, Insightful

      Using a quantum computer it can search every possible key simultaneously, cracking the encryption almost instantly.

      My understanding was that this is not true. At best you get the square root of the number of steps that would be required for a non-quantum brute force search. This means that key sizes are effectively halved, but that isn't an insurmountable problem.

      A bigger problem is that some algorithms are intrinsically vulnerable to quantum computing (or to rephrase, take far, far fewer steps to reverse on a quantum computer than a classical one). Factoring is one such case, which is why quantum computing spells the death of RSA. Most other algorithms are relatively safe, if I understand correctly (or at least, have no known quantum computing cracking method beyond brute force; this may change, unless they're _proven_ to have no other cracking method).

      In summary, quantum computing is powerful, but not a magic wand that makes all classical encryption schemes invalid.

    28. Re:Secure communications? by Anonymous Coward · · Score: 0

      Uh, that should read "terrorists and citizens with undesirable opinions" :-)

    29. Re:Secure communications? by d474 · · Score: 1

      Yeah, but the cool part is that my nanobots are perfectly transparent. Once the code is decrypted, the intended recipient doesn't notice my bots on the surface of his computer monitor recording his secret message while he reads it.

      Cryptography doesn't need to be broken, sooner or later, it breaks it's self. You just need to be there when it happens.

      --
      Authority questions you. Return the favor.
    30. Re:Secure communications? by Anonymous Coward · · Score: 0

      It can't know. Hence it's pretty easy to remain undetected. You just have to throw it a few curves. The result won't be cryptographically secure (i.e., secure if all but the key is known) since parts of your encryption/decryption process will need to remain secret. However, if you can manage that then it will keep your message from being decrypted, and there's no arguing with success. Crypto will always be more powerful than cryptanalysis or key bashing. Encrypting is just way too simple and cheap compared to decrypting.

    31. Re:Secure communications? by bigberk · · Score: 3, Interesting
      if eavesdropping on the encrypted transmission destroys it, couldnt the eavesdropper do so on purpose everytime, effectively jamming all transmission?
      Definitely. The main problem with practical quantum crypto communications is this issue of information loss due to noise or tampering. If you could send photons over a lossless link (impossibility) then you guarantee entirely protected communications, or easy detection of tampering/eavesdropping.

      But since real transmission lines (even the best optic fibers) will always lose photons, you have to start adding on complicated processing to deal with the losses. Were the photons lost due to natural causes, or is someone eavesdropping? And if data is duplicated to account for losses, the system can possibly be tricked by an attacker into revealing information. This is a delicate subject and a great cause of complication in the field!

      The communications can also be jammed of course but the focus of the technology is delivering a secure link.
    32. Re:Secure communications? by maxwell+demon · · Score: 1

      You mean, quantum computers will not be DOS compatible? Well, you know, a computer that doesn't run DOS has obviously no future. :-)

      --
      The Tao of math: The numbers you can count are not the real numbers.
    33. Re:Secure communications? by danila · · Score: 1

      It's all about spin. :) There is a library of stock phrases in every news outlet. The journalists simply pick some for each story. For example, I can predict that the next nanotechnology story will say that it can be used to diagnose/treat cancer (perhaps, specifically breast cancer), whether it's relevant or not.

      --
      Future Wiki -- If you don't think about the future, you cannot have one.
    34. Re:Secure communications? by maxwell+demon · · Score: 1

      Basically the same as what happens if you do a classical measurement: No meaningful data can be extracted.

      And no, the computing power of quantum computers is not unlimited. Indeed, the set of problems which can be solved on quantum computers is exactly the same which can be solved on classical ones. It's just that a quantum computer can solve some problems much faster than a classical computer.

      --
      The Tao of math: The numbers you can count are not the real numbers.
    35. Re:Secure communications? by rozz · · Score: 1
      So which is it, secure communications or communications that can be spied on? It can't be both.

      which only demonstrates that u have no ideea about this "quantum computing" stuff ... and the moderators can easily sing along ...
      the "uncertainty principle" is a main ingredient in quantum teory and one of the worst brain twists in quantum is exactly "IT CAN BE BOTH"!

      check this classic quantum jokes for example(source wikipedia.org) :
      "Quantum mechanics provides probabilistic results because the physical universe is itself probabilistic rather than deterministic."
      "one state can exist in superposition of all possible states at once."
      "Quantum information cannot generally be read or duplicated without disturbance"

      in other words here's how a password sniffer based on quatum technology works:
      1. sniff the encrypted password - success
      2. decrypt the password - success
      alert, alert, system/communication insecure!
      3. read/use decrypted password - failed! (Quantum info cannot be read without disturbance)
      oh sorry, false alarm, system is 100% secure

      but dont any of u worry, according to Niels Bohr you are on the best path :
      "Those who are not shocked when they first come across quantum mechanics cannot possibly have understood it."

      --
      "There is nothing more frightful than ignorance in action." Johann Wolfgang von Goethe
    36. Re:Secure communications? by Anonymous Coward · · Score: 0

      no, no it shouldnt. they are one in the same.

    37. Re:Secure communications? by RidiculousPie · · Score: 1

      Yeah.

      Strange but true.

      You should read what it says about me in other books.

      --
      ah, mod points ... now where is my crack?
    38. Re:Secure communications? by _Knots · · Score: 1

      Close but not quite....

      Generating bits takes a lot of time so you generally only generate a shared secret for use with another symmetric cipher scheme; this is often a lot shorter than your message.

      You don't gain complete knowledge of which bits are compromised as you are forced to disclose bits over a potentially insecure channel (if you had a secure one, why are you doing this in the first place??) which renders them useless for shared secret usage even if they're not compromised. But disclosing lets you match up bits and say (with high probability) that nobody's snooping on your line, so the undisclosed bits are the same (they'd not be in the advent of somebody fooling on the line).

      --
      Anarchy$ dd if=/dev/random of=~/.signature bs=120 count=1
    39. Re:Secure communications? by Ckwop · · Score: 1

      So which is it, secure communications or communications that can be spied on? It can't be both.

      It can be and is both. Secure is an adjective - without context it's meaningless. In the context of a traditional factoring/discrete log based key exchange protocol then quantum computers will see a swift end to that period of history. Shors algorithm can factor in the worst case in around log(n)^3 time and log(n) space.

      As for other ciphers, such as AES, i'd say it's fairly likely that there will be clever attacks using Quantum computers against these traditional designs but I doubt the attacks will capture be general enough to attack all ciphers you can make on a conventional computer.

      At any rate the problem of keeping a message secret has been solved for the best part of a 90 years in the form of the Vernam Cipher. Even a quantum computer can't break this construction. The problem with it is that the key is the same length as the text you want to encrypt. If you have a secure channel capable of moving a n-bit key between two people then why not move the actualy message?

      What's interesting is that someone discovered how to make a quantum mechanical channel that allows you to agree bits for use with a Vernam cipher that can detect when anyone trys to eavesdrop on the line. This channel only allows you to communicate random bits between each other but that's okay because we can use the Vernam cipher to protect a message with actual meaning and obtain perfect secrecy.

      Since you can tell if a bit has been read by a third-part you can be safe in the knowledge that you have in fact swapped your key in secrecy and thus the message is unreadable.

      Simon

    40. Re:Secure communications? by Tyler+Durden · · Score: 1
      Using a quantum computer it can search every possible key simultaneously, cracking the encryption almost instantly.

      Acutally, that's not true. The quantum algorithms created to break numbers into their prime components are able to solve the problem in polynomial time when it is believed to be solvable at best in exponential time under classical computing. Much much quicker, but not instantaneous, which would be a quick instance of constant time.

      --
      Happy people make bad consumers.
    41. Re:Secure communications? by randombit · · Score: 3, Informative

      My understanding was that this is not true. At best you get the square root of the number of steps that would be required for a non-quantum brute force search. This means that key sizes are effectively halved, but that isn't an insurmountable problem.

      Bingo. Which is why the AES competition required support for 256 bit keys, when even 128 bits is out of reach by any conceivable technology.

      Factoring is one such case, which is why quantum computing spells the death of RSA.

      Not true, necessarily. Shor's algorithm is algorithmically faster than the generalized number field sieve, but there is a constant in there. We don't know how big that constant is, and we won't until we have a quantum computer big enough to run Shor's algorithm (30 qubits or so, IIRC). It's entirely possible that Shor's algorithm is only faster then the GNFS once you hit keysizes of 10,000 bits, in which case it doesn't matter. OTOH, if Shor's algorithm is faster than the GNFS on 256 bit keys, we are, indeed, in some trouble. Of course running Shor's algorithm on a 1024 bit RSA key would take quite a large quantum computer, too.

      And, as you mention, there is no algorithm for compute discrete logarithms much faster than usual on quantum computers. I haven't heard about such an algorithm, anyway. Doesn't mean it doesn't exist, of course.

      Summary: algorithmic complexity is not the sole determinant of algorithm running time.

      In summary, quantum computing is powerful, but not a magic wand that makes all classical encryption schemes invalid.

      Thank you. Every time a quantum crypto or quantum computing store pops up here, the hype level seems to increase by several orders of magnitude. It's really annoying.

    42. Re:Secure communications? by jazmataz23 · · Score: 1
      I don't understand your first assertion. One half of a number is not the same as its square root. Even a key length of nine, the square root is 1/3 the key length. For a 100-digit key, the square root is a tenth. Please explain how this "halves" the key size.

      I'm not a cryptographer, but I think the advantage of using a quantum computer *is* the fact that it can do a brute-force search exponentially faster than today's hardware. If there were some magic factoring algorithm that quantum computers can do, then that algorithm could be applied in a classical computer (abeit much slower). It's not that quantum computers are "better" at factoring, necessarily.

      The key to our current system of secure communications is that each time you increase the key by one bit, you double the size of the keyspace. This doubles the time to brute-force examine those new possibilities on a traditional binary computer, since it must check each key in series. Thus, the time to brute-force attack a key of binary length n is 2^n. The quantum computer uses qubits, which rather than being 1 or 0, allows a superposition of both 1 and 0 (vastly simplifying the situation here for clarity and due to a lack of strong understanding myself). This allows a quantum computer of n qubits to check every key of length n in one step, or a linear growth in time with keysize. Compared to 2^n, or exponential growth, you can see how much easier it is to search a keyspace using this technology.

      Now, there are many other ways to aproach breaking a cypher, as there are such things as "weak keys" for a given cryptosystem, (the cryptographic version of choosing "password" as your password) but I'd be getting off our discussion (and frankly out of my depth).

      jaz

      --
      Death to Argument by Slogan!! (This post twice-encrypted with ROT-13. Replies not using same will be ignored)
    43. Re:Secure communications? by YellowG · · Score: 1

      secure communications and easily decoded encrypted communications.

      It's Quantum Physics.

      of course it can be both!!!

    44. Re:Secure communications? by Christopher+Thomas · · Score: 1

      I don't understand your first assertion. One half of a number is not the same as its square root. Even a key length of nine, the square root is 1/3 the key length. For a 100-digit key, the square root is a tenth. Please explain how this "halves" the key size.

      A key with 1024 bits has 2^1024 possible values. A key with 2048 bits has 2^2048 possible values. The square root of 2^2048 is 2^1024.

      A classical computer brute-force searching a 2048-bit key value requires 2^2048 tests. A quantum computer requires only sqrt(2^2048), which is (2^1024) - the number of operations a classical computer would require to brute-force a key of half the length (1024 bits).

      I hope this clears up your question.

      I'm not a cryptographer, but I think the advantage of using a quantum computer *is* the fact that it can do a brute-force search exponentially faster than today's hardware.

      It can't, in any scheme where you have to actually get data back out of the quantum computer.

      Whenever you observe the state, it collapses to a specific value. You have to do a number of tests on the same computation result to get an idea of what the probability distribution is. This takes enough operations to produce the "square root" figure quoted. You only get better than that if the algorithm you're trying to reverse lends itself specifically to a quantum implementation (like Shor's algorithm for factoring).

      Someone more heavily into QC can give you a more detailed description of how this works.

    45. Re:Secure communications? by jazmataz23 · · Score: 1
      No, thanks, that was a lot clearer. Doubling the bit length is a lot different than doubling the number!

      Thanks for the reader's digest version about about how "calculations" are actually conducted using quantum machinery. I'd read an article about Shor's algorithm a long time ago (when IBM factored 15 into 3x5), but found a much more informative article about how it was done on the wikipedia by googl'ing Shor's.

      jaz

      --
      Death to Argument by Slogan!! (This post twice-encrypted with ROT-13. Replies not using same will be ignored)
    46. Re:Secure communications? by Anonymous Coward · · Score: 0

      Secure.... quantum computing promises enough mathematical processing power to unravel encryption in very little time. However, quantum computing also allows us to CREATE mind-blowingly complex encryption. I feel all of this concern is probably unjustified. There are other developments now in play that may just make encryption unneccisary by using quantum states at either end to actively verify data validity by comparing states with eachother. I don't remember who is doing this but It was mentioned sometime last year.

    47. Re:Secure communications? by jongleur · · Score: 1
      if eavesdropping on the encrypted transmission destroys it, couldnt the eavesdropper do so on purpose everytime, effectively jamming all transmission? Little point in having a secure way to communicate if no message can ever get through.

      I think that it may be argued that it is better to secretly know your opponent's plans than it is to stop his planning.

      If one communication channel is too disrupted, your opponent will presumably seek another channel, one you don't know about, or can't affect.

      This is large part was the basis of the decision to keep the existence of the British Enigma machine a secret during WWII. Even though a lot of the message traffic for the German U-Boats was decoded, the information was used sparingly in order to keep the Germans from deducing that their traffic was being read.

  3. Hong Wen Jiang also admits by Anonymous Coward · · Score: 0

    That he'll be a script writer for Enterprise starting this season.

    1. Re:Hong Wen Jiang also admits by Bender+Unit+22 · · Score: 1

      No need, with both Nazi's and aliens together they can't miss, it is gonna be one hell of a show. I just can't figure out what it has to do with Star Trek. :)

  4. Now that's a huge hard drive... by zeux · · Score: 3, Insightful

    From the article:
    "With 100 transistors, each containing one of these electrons, you could have the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around," Yablonovitch said. "And why stop with 100 transistors?"

    Of course, because with 101 transistors you could store as many Library of Congress as there are electrons in the visible universe on a disk the size of 2 square hogs for a duration of up to 3.4256 parsecs.

    Unfortunately, it will take up to as many (1/98742) of year as it took in seconds for Apollo 11 to reach the moon from the launch pad to design such a hard-drive.

    Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

    1. Re:Now that's a huge hard drive... by frenetic3 · · Score: 1

      i'm not a quantum physicist (sorry for not using a lame IANA* acronym) but i believe that since quantum bits can represent both 1 and 0 at the same time and thus through all the permutations of those 100 bits (2^100 states) could represent that much data -- since all possible states are represented simultaneously? again, i'm fuzzy on the details, but this could get you started wikipedia entry for qubit and there's some info on quantum entanglement that i havent chewed through yet that seems to be the basis for this.

      -fren

      --
      "Where are we going, and why am I in this handbasket?"
    2. Re:Now that's a huge hard drive... by Tim+C · · Score: 1

      I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

      Well, let's estimate that 1 million hard drives are made each year, at an average capacity of 200gig (both figures pulled out of the air; I have no idea how many hard drives will be made this year). That's a total capacity of 0.2 billion GB/year.

      The age of the universe is estimated to be somewhere around 14 billion years, so that gives us 2.8 billion billion GB.

      Seems simple to me, but then my degree is in Physics, so I'm used to that sort of crap :-)

    3. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0
      for a duration of up to 3.4256 parsecs.

      A parsec is a distance, not a time.

      From Google, 1 Parsec = 3.08568025 × 1016 meters

    4. Re:Now that's a huge hard drive... by sp0rk173 · · Score: 1

      They're simply relational units, rather than arbitrary ones (ie, bits and bytes). Most people have no freaking clue what a bit or a byte is, only how it relates to their life...they know a bit is probably pretty small, and 900 gigabytes is probably enough to store quite a bit of porn and mp3's. People also realize that a crapload of hardisks where made this year which translates to a several large craploads of disk space, and the universe is at least 6000 years old, but probably a whole lot older...so that means the storage corresponds to..

      (several large craploads of diskspace)*(X), where X is >= 6000

      of course, what this really means is, "a whole lot." So much so that if they were to quantify it your head would explode and your spinal chord would shoot out your ass.

    5. Re:Now that's a huge hard drive... by zeux · · Score: 1

      This has been discussed again and again on slashdot. That's why I put it there, some people could prove you it is also a time unit.

    6. Re:Now that's a huge hard drive... by saigon_from_europe · · Score: 1
      Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.
      It is imperial unit for large amount of data, you insensitive clod!
      --
      No sig today.
    7. Re:Now that's a huge hard drive... by Smitty825 · · Score: 1

      I'd guess slighty more than 1 million hard drives are made in a year. According to this article, Apple shipped 876,000 Macs and 860,000 iPods last quarter. That's 1.6 million hard drives shipped by one (small) vendor in a quarter, so you'll need to up your numbers :-)

      --

      Doh!
    8. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0
      For your education:

      How Far is a Parsec?
      Check out google if you need more convincing.

      People can try to prove a lot of things. People can also be wrong.

    9. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0

      why does everyone call it a "spork"? it should be called a "foon"...since it's 1/4 fork and 3/4 spoon.

      or maybe we should call it "the greatest advancement in eating utensils in the history of the universe".

      if only they could combine it with the cutting power of a knife...if they did, i'd line my whole drawer with foons!

    10. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0

      Come now, since time and distance are related by the speed of light c, any unit of distance can also be used as a measure of time.
      I mean you don't hear the same complaint when people use the [light] year as a measure of distance (And measuring distances based on the distance light travels in the time it takes for a ball of rock to move around a gas cloud is pretty arbitrary).
      By using 'parsec' in the context of time he was obviously refering to the inverse-light parsec (based on your link it looks like 3.26 years).

    11. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0

      Most of those units are science writer units and not scientists units. Do you actually thing the researchers write these articles?

    12. Re:Now that's a huge hard drive... by zeux · · Score: 1

      Thank you.

    13. Re:Now that's a huge hard drive... by wfberg · · Score: 1

      I mean you don't hear the same complaint when people use the [light] year as a measure of distance
      No because it IS a measure of distance.
      1 lightyear = 1 * the speed of light * 1 year = 9.4605284 × 1015 meters.

      Just because "thespeedof" is left out, doesn't make "lightyear" a unit of time; in much the same way that when us Europeans say we want "5 kilos" of something, we actually expect 5 kilograms, and not kiloWatts or some nonsense like that.


      By using 'parsec' in the context of time he was obviously refering to the inverse-light parsec (based on your link it looks like 3.26 years).


      If you use "meter" in the context of time, what the fudge does that mean?

      Oh and btw, behold the power of google (1 Parsec) / the speed of light = 3.26163626 years.

      --
      SCO employee? Check out the bounty
    14. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0

      (parsec/velocity) is a unit of time. parsec is not.
      (velocity*time) is a unit of distance. time is not. That's why a light-year is a valid measure of distance: speed of light * one year.
      Simple as that.

      It's convenient that the velocity of light is constant. It makes for some interesting consequences. I think Einstein wrote something about it. But the Millenium Falcon and a photon are not going to travel a parsec in the same amount of time, so using a parsec as a unit of time is pretty useless. When talking about a standard of measure, the measure needs to apply uniformly or it's useless. Kind of like when the distance of 1 foot was defined by the size of the current king's foot. When a new king came into power did everybody's houses suddenly change size?

      I suppose it could be fun measuring the volume of my water bottle in seconds^3, but that wouldn't be right. It would have to be light-seconds^3. That one actually makes sense.

    15. Re:Now that's a huge hard drive... by sp0rk173 · · Score: 1

      Ah, someone after my own heart. Did you know that sporks existed before good ol' JC walked the earth? Granted, not in the form they are today, but they existed! I actually have a titanium spork, it's the best utensil i've ever used, not to mention extremely light. I believe the name spork has been around for a while, foon is of course its close rival. I'm not sure if it's a trademark or not.

    16. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 1, Informative

      how about a lot more then the amount of pr0n you can watch during your lifetime?

    17. Re:Now that's a huge hard drive... by Jad+LaFields · · Score: 1

      I prefer to use the standard "metric buttload" to measure my large amounts.

      --
      [SIG] It's like putting a moose in the blender -- a recipe for disaster!
    18. Re:Now that's a huge hard drive... by Epistax · · Score: 0

      Sorry-- how many volkswagon beetles is that?

    19. Re:Now that's a huge hard drive... by Terrasque · · Score: 0

      42!

      --
      It's The Golden Rule: "He who has the gold makes the rules."
    20. Re:Now that's a huge hard drive... by glitch23 · · Score: 1

      Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

      Does the phrase "a lot" mean anything to you?

      --
      this nation, under God, shall have a new birth of freedom. -- Lincoln, Gettysburg Address
    21. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0

      actually nasa has determined the age of the universe to an impressive degree of accuracy by looking and measuring dark matter (or was it dark energy?) in the universe, and determined its 13.7 billion yrs

    22. Re:Now that's a huge hard drive... by aminorex · · Score: 1

      when europeans use 'kilograms' they almost always
      mean 'units of 9.81 newtons'. go figure.

      --
      -I like my women like I like my tea: green-
    23. Re:Now that's a huge hard drive... by ElliotLee · · Score: 1
      Apple shipped 876,000 Macs and 860,000 iPods last quarter. That's 1.6 million hard drives shipped by one (small) vendor in a quarter


      So if Apple has a 5% market share, the total number of hard drives shipped per quarter is 32 million. Four quarters in a year gives us 128 million per year.


      Using an average capacity of 200 GB, we get 6.4 billion GB/year. "The age of the universe is estimated to be somewhere around 14 billion years", so we have 89.6 billion billion GB.


      To put that in better perspective, it also equals 8.77929688 × 10^16 terabytes (thanks Google calculator). Also known as 8.5735321 × 1013 petabytes...


      85,735,321,000,000 petabytes.


      Phenomenal, really.

    24. Re:Now that's a huge hard drive... by vrmlknight · · Score: 1

      You may want to look up Bloch spheres for more info.
      It's a representation of the pure state space of a 2-level quantum mechanical system so think of that being the equivalent of a Bit but because you are talking about the surface area of a sphere you can do allot more with it....

      --
      This must be Thursday, I never could get the hang of Thursdays.
    25. Re:Now that's a huge hard drive... by markh1967 · · Score: 1

      Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

      I don't think it really matters exactly how large it is; it will never be used because it will take years to format it.

      --
      Input error. Replace user and press any key to continue.
    26. Re:Now that's a huge hard drive... by Anonymous Coward · · Score: 0

      Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

      Let me put it in extremely simple terms.

      It can hold a shitload of data.

    27. Re:Now that's a huge hard drive... by nusuth · · Score: 1

      That doesn't make any sense. The number is roughly equal to 2^100. If every electron cannot assume about 2^95 distinct and detectable spin states, I think we are grossly misunderstanding the word "implict" in the original.

      --

      Gentlemen, you can't fight in here, this is the War Room!

    28. Re:Now that's a huge hard drive... by RWerp · · Score: 1

      Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

      They don't put such stuff into research papers, but many of them believe that ordinary people will be more impressed by such comparisons.

      --
      "Long run is a misleading guide to current affairs. In the long run we are all dead." (John Maynard Keynes)
  5. I done burned me fingers. by Kenja · · Score: 1
    "Quantum Computing Using Traditional Transistors"

    That should like a LOT of soldering.

    --

    "Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
    1. Re:I done burned me fingers. by Anonymous Coward · · Score: 0

      shut up or learn to speel

  6. That's weird by Anonymous Coward · · Score: 4, Funny

    The article said something totally different brfore I clicked it.

    1. Re:That's weird by orangesquid · · Score: 1, Funny

      It was in a quantum super-state. The act of observation (By clicking Read more...) made it evaluate to a particular single state.

      You might also notice that, now that you know what the whole article says, you don't know how long it took to load. If instead you had timed the page load, you wouldn't have been able to read the article.

      --
      --TheOrangeSquid Is it any wonder things seem so awry? We swim in a sea of confusion and don't have to think to survive
  7. Hrmm... by Arcanix · · Score: 5, Funny

    I thought about reading the article but will it change if I look at it?

    1. Re:Hrmm... by Anonymous Coward · · Score: 0

      Cue Star Trek reference...

      Only if you fail to use your Heisenberg Compensator!!!

    2. Re:Hrmm... by mystik · · Score: 1, Funny

      Yes, it'll change to 403 Service Unavailable.

      --
      Why aren't you encrypting your e-mail?
    3. Re:Hrmm... by microwave_EE · · Score: 1, Funny

      That is...

      if you fail to use your Heisenberg-Compensated Web Browser (TM)

      Dang my years of ST TNG watching...can't sort out episodes.

      --
      I'll take you to the ball, Barbara Manitee!!!
    4. Re:Hrmm... by BrokenStructure · · Score: 1

      from a quantum perspective, its existence is not determined until your senses (most likely your eyes in this case) give measurement to it. *shrugs*

    5. Re:Hrmm... by gardyloo · · Score: 1

      Don't worry -- even if it changes, it'll be reposted next week, and maybe the week after that. This is /., you know. And you can just look at it each time and get an expectation value....

    6. Re:Hrmm... by cfuse · · Score: 1
      I thought about reading the article but will it change if I look at it?

      You'll never know.

  8. wow! by quelrods · · Score: 3, Informative

    This would be something to help drive down the cost. Quantum computing on the desktop would finally be a evolutionary step in computing. (Up'ing clockspeed constantly and decreasing chip size is not evolutionary.) Though, quantum computing on the desktop probably means time to stop using passwords due to sheer power to brute force them.

    --
    :(){ :|:&};:
    1. Re:wow! by geekoid · · Score: 3, Insightful

      "(Up'ing clockspeed constantly and decreasing chip size is not evolutionary.) "

      actually, it is evolutionary, just not revolutionary.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    2. Re:wow! by Anonymous Coward · · Score: 0

      You have confused evolutionary and revolutionary. Quantum computing is mostly the later, though it doesn't make anything decidable that wasn't already so on a classic machine (computability theory). It does offer some benefits in the complexity theory sense (Shor's factoring algorithm).

    3. Re:wow! by pilgrim23 · · Score: 1

      Qunatum still makes drives? Oh sorry, wrong stop, I am from the multiverse next door.

      --
      - Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.
    4. Re:wow! by rokzy · · Score: 1

      this has no chance of making it to the desktop. the US government will declare it a threat to national security and ban its domestic use or export.

    5. Re:wow! by Anonymous Coward · · Score: 0
      Of course Quantum computing on the desktop would finally be a evolutionary

      Think of all the multiverse transparent eyecandy!

    6. Re:wow! by bondero · · Score: 1

      This would be something to help drive down the cost. Quantum computing on the desktop would finally be a evolutionary step in computing. (Up'ing clockspeed constantly and decreasing chip size is not evolutionary.) Though, quantum computing on the desktop probably means time to stop using passwords due to sheer power to brute force them.

      Actually, since all security measures are some form of password (for example, a fingerprint is just a really long password) there will be no way of securing information. Interesting.

      Eitan

      --
      -- You're on a first name basis with Lucidity. I have to call it Mr. Lucidity, and that's no good in a pinch.
    7. Re:wow! by Anonymous Coward · · Score: 0

      A random 8-character password will still be extremely secure if you disable the account for just 1 millisecond after each unsuccessful attempt (provided that you don't let the world read the password file). Doing the math (case sensitive, including digits = 62 values): 62^8 / 1,000 / 60 / 60 / 24 / 365.24 = ~6,919 years.

      However, we will need more powerful methods of encrypting data transmission...

  9. Kind of misleading... by 7Ghent · · Score: 5, Informative

    They're actually using pulsed microwave bursts to manipulate the electron's spin, not the transistor itself, really.

    1. Re:Kind of misleading... by QuantumG · · Score: 2, Insightful

      Well seeing as you can lay down a junction on a silicon die that can produce that microwave burst just as easily as you can lay down a transistor the basic principle that you can do quantum computing with silicon is still being demonstrated.

      --
      How we know is more important than what we know.
  10. Tin Foil Hat Time... by CommanderData · · Score: 4, Insightful

    From the article:
    Quantum computing, which holds the promise of nearly unlimited processing power, secure communications and the ability to decode encrypted conversations by terrorists and others (emphasis mine)

    Take special note of the word others, which should be read as everyone. The government will be falling all over themselves to support this research and inherit a technology that makes encryption virtually useless.

    I'm all for advancing technology, and no doubt quantum computing will be a great leap forward. It's just a shame that our privacy will be sacrificed in the process.

    --
    Urge to post... fading... fading... RISING!... fading... fading... gone.
    1. Re:Tin Foil Hat Time... by AuMatar · · Score: 1

      Of course, the government also uses encryption, and they don't want theirs to be useless.

      --
      I still have more fans than freaks. WTF is wrong with you people?
    2. Re:Tin Foil Hat Time... by Anonymous Coward · · Score: 0

      True, and that's the real trick. The government will need to control this technology so that citizens or other countries never get their hands on it. Strong encryption products are classified in a way that makes exporting them from the US illegal. They'll just take the next logical step with quantum computing and make it illegal for civilian use!

    3. Re:Tin Foil Hat Time... by Owndapan · · Score: 1
      Quantum computing will allow for more secure encryption to what is currently available. It can crack today's encryption easily, but tomorrow's may be a different matter.

      So don't give up and go putting all your private data on P2P just yet.

    4. Re:Tin Foil Hat Time... by Anonymous Coward · · Score: 0

      Relax dude, there's already the ultimate encryption scheme out there and it doesn't have anything to do with quantum mechanics. It's called steganography, and it works. Expect it to become more popular in the coming years as creating, processing, transmitting and storing huge quantities of data becomes easier and easier.

    5. Re:Tin Foil Hat Time... by Anonymous Coward · · Score: 1, Insightful

      If you become a "person of interest," you have no privacy. Neither do you control if or when you become a person of interest. Some dipshit in your workgroup can do questionable things without informing you, yet you go under the microscope, guilty by association.

      One might argue that it would be better to live with an open kimono all the time. If everybody could know everything about you all the time, on demand, your whole life history from beginning to end in any format that might be desired, inside out and outside in, and you could know everything about anybody else...

      fortunately I will be dead before they work it out

    6. Re:Tin Foil Hat Time... by iamdrscience · · Score: 1

      Yes, but while Quantum computing allows current encryption to be cracked, it also allows use of stronger encryption which is equally difficult to crack.

      So supposing there's some impossible miracle breakthrough and by this time next year we've all got quantum computers on our desktop. Any communications you made previous would be crackable, but everything you were doing at the time would still be secure. I can't speak for everyone, but for most places you use encryption in your daily life, the information becomes stale and nearly useless pretty quickly. Governments (and terrorists) are probably in a different situation though.

    7. Re:Tin Foil Hat Time... by BrokenStructure · · Score: 1

      you're just going to have to get used to it. It's only a matter of time before privacy is a foreign idea. I think it's an exciting idea, though. People will have to learn to love each other and themselves for who they really are. If they can't accept, then they're going to suffer. What do you think?

    8. Re:Tin Foil Hat Time... by AtomicBomb · · Score: 1

      No worries. In the past, we use something not much better than ROT13. The best one that we got was probably ENIGMA before the computer age. They are pretty robust against the arithmatic ability of human brain.

      The currently using ones (public key encryption, DES3 etc) are all developed with silicon computers in mind. While they will become obsolete with quantum computing, I will be surprised if we cannot develop something better by then...

    9. Re:Tin Foil Hat Time... by yohanes · · Score: 1

      You might want to take a look at Quantum Cryptography

    10. Re:Tin Foil Hat Time... by Anonymous Coward · · Score: 0

      I'm so sick of this myth being perpetuated in these discussions. QUANTUM COMPUTING IS NOT THE END OF CLASSICAL CRYPTOGRAPHY. It never was, but people seem to think for some reason that increased computational speed is a problem for classical crypto. It's not. All you have to do is increase the keylength. Yes, Grover's algorithm can brute force search in a square root of the time it would take a classical machine, but this only cuts the number of key bits in half. So, DOUBLE THE KEY BITS, silly! Problem solved. The idea that even a quantum computer is "infinitely fast" is utter rubbish: extracting the result of the computation takes much longer than performing it in the first place, so as a practical matter you still have to wait a long time to get your answer.

    11. Re:Tin Foil Hat Time... by Rich0 · · Score: 1

      What form of stronger encryption are you referring to - quantum crypto?

      If so - that is hardly a substitute for RSA. RSA works between two computers anywhere who have never had contact. QC works between two computers that have a direct physical link between them. So, if you want to send a QC message from your home to your friend across town, you'll need either a fiber optic line or maybe a laser mounted on a pole high above your house pointed at his house. Not exactly a trivial thing to set up...

    12. Re:Tin Foil Hat Time... by Rich0 · · Score: 1

      Uh - you do realize that QC requires a direct point-to-point link to work, right?

      How would your propose to send a QC packet from your computer to mine? Assume that you're in Texas, and I'm in Helsinki. I don't think there is any technology that could create a single physical link without any retransmission between those locations. Maybe you could have an indirect link via a satellite. Of course, now whoever owns the satellite can intercept your transmission (since QC only prevents interception between points - the message is not QC in the satellite between when it is received and retransmitted). In fact, the satellite owner using QC could be fully aware that your uplink is being intercepted but could choose to pretend that it is not and neither party would know. Think of it like sending email from me to you, with SSL-encrypted connections between my email client and my ISP SMTP server, between my ISP and your ISP, and between your ISP POP3 server and your mail client. Completely secure from everyone - except the two ISPs.

      QC is great for securing physical links between two points. However, over a large network it requires you to trust every node of the network - which is usually not wise...

    13. Re:Tin Foil Hat Time... by Glock27 · · Score: 1
      Relax dude, there's already the ultimate encryption scheme out there and it doesn't have anything to do with quantum mechanics. It's called steganography, and it works. Expect it to become more popular in the coming years as creating, processing, transmitting and storing huge quantities of data becomes easier and easier.

      Steganography is the process of hiding (possibly encrypted) data in the low-order areas of other files, often multimedia files like pictures and music. This information is (often readily) detectable, and once detected is no more secure than any other information. In other words, right now most people would use PGP or the equivalent to encrypt the information they're hiding steganographically - which could be broken by quantum computers.

      For more information, check out this, or for the more technically inclined read the steganography and steganalysis section here. Good stuff.

      In order to do anything practical, all the qubits in a quantum computer must be entangled - which is apparently the hard part. So, in order to break information encoded with a 2048 bit key, 2048 entangled qubits will have to be available. Anyone have any insight as to when that might happen? Is there anything intrinsically harder about entangling more qubits, or is the leap from say eight to 2048 straightforward?

      Quantum computers will, if they work as advertised, break all RSA type public key encryption. Does anyone know if ECC is also vulnerable?

      OK, that's enough questions for now... ;-) TIA for any answers.

      --
      Galileo: "The Earth revolves around the Sun!"
      Score: -1 100% Flamebait
    14. Re:Tin Foil Hat Time... by Glock27 · · Score: 1
      Well having done a little research I find that the following is wrong:

      In order to do anything practical, all the qubits in a quantum computer must be entangled - which is apparently the hard part. So, in order to break information encoded with a 2048 bit key, 2048 entangled qubits will have to be available. Anyone have any insight as to when that might happen? Is there anything intrinsically harder about entangling more qubits, or is the leap from say eight to 2048 straightforward?

      Instead, it's (courtesy of Wikipedia):

      For a 1000 bit number, this implies a need for 1e12 to 1e18 qubits. Fabrication and control of this large number of qubits is non-trivial for any of the proposed designs.

      So, I'd say that our (large keysize) encrypted data is safe for now... ;-)

      --
      Galileo: "The Earth revolves around the Sun!"
      Score: -1 100% Flamebait
    15. Re:Tin Foil Hat Time... by meatspray · · Score: 1

      By all means put the hat on, but don't close the lid on the box yet.

      Just because technology will thrust forward to decode the current encryption, doesn't mean the end of encryption. It just means there will be a lull while we use the new hyper fast technology to creat a new level of encryption.

      Computer technology ended up making simple machine encryption useless, then computer age encryption came about and was secure. When quantum computer technology makes Simple computer encryption useless, encryption born of the quantum computer technology will no doubt come about and be safe from the current tech of that age. (then something faster comes along...yada...yada...yada)

  11. How long before I can turn my transistor radio by Anonymous Coward · · Score: 2, Funny

    ...to a quantum radio? I want to pull in stations from alternate universes since there is no good local music.

    1. Re:How long before I can turn my transistor radio by Anonymous Coward · · Score: 0

      An infinite number of universes and still nothing good on the quantum radio...

    2. Re:How long before I can turn my transistor radio by Just+Some+Guy · · Score: 1
      Yeah, because I want to hear KlearChannel, CleerZhanul, KleahChaunuh and an infinite number of variants on "The Greatest Hits of the ($decade - 2)s, ($decade - 1)s, And Today!"

      I wonder how many times AlternaBritney's been married, and how many times she's sung about it?

      --
      Dewey, what part of this looks like authorities should be involved?
  12. Terrorism. by CosmeticLobotamy · · Score: 1

    "secure communications and the ability to decode encrypted conversations by terrorists and others"

    Why does every article about anything have to have the word "terrorist" in it, these days?

    1. Re:Terrorism. by Anonymous Coward · · Score: 0

      Why does every article about anything have to have the word "terrorist" in it, these days?

      Because "terrorist" is the new "hacker."

    2. Re:Terrorism. by emeitner · · Score: 3, Insightful

      Fear sells.

      --
      Guru Meditation #6d416769.21610a21
    3. Re:Terrorism. by idlemachine · · Score: 1

      Because you sound like a paranoid moron if you continue to use "communist".

    4. Re:Terrorism. by Anonymous Coward · · Score: 0

      Becasue the word gives you a +1 moderation bonus so people are more likely to pay attention to your post.

    5. Re:Terrorism. by 1u3hr · · Score: 1
      Why does every article about anything have to have the word "terrorist" in it, these days?

      The guy is "Eli Yablonovitch, UCLA professor of electrical engineering, director of UCLA's Center for Nanoscience Innovation for Defense", so it'll help to get more funding (almost wrote "FUDding" there, I wonder why?).

  13. Secure Communications ... by mdvlspwn99 · · Score: 4, Insightful

    is great. Until the technology becomes ubiquitous enough that even terrorists have access to it. Then what? It's secure...even from us.

    --
    If reality was like Slashdot, most people would be (-1) Redundant.
    1. Re:Secure Communications ... by utexaspunk · · Score: 1

      then we'll just be where we are right now. big deal. we can't argue that all human beings have the right to free speech and the right to privacy* (*except for terrorists)

      no, we'll just have to figure out how to protect ourselves another way. maybe terrorism should just be viewed as a crime of opportunity. we can do lots of things to prevent the opportunity for terrorism from occurring without even infringing on people's rights. consider that proper pilot training and some secure cockpit doors could have prevented the attacks of 9/11/01 from occuring.

      look at it this way- you want the terrorists to have privacy, because what's to keep you from being branded a terrorist?

    2. Re:Secure Communications ... by andrew_mike · · Score: 1

      I wouldn't worry too much about quantum encryption getting out if the open. I'll bet the NSA's just waiting until someone develops a good solution before they ste -- uh, appropriate it and apply secrecy orders all around.

      Consider: they had encryption in the bag in the '50s and '60s. Nobody was safe from them, except possibly other intelligence agencies. Then Rivest, Shamir, and Adleman came up with a public-key encryption method that blew the NSA out of the water. After that, the NSA had no chance for redemption. Attempting to trick the encryption people to work for them (through co-opted NSF grants) didn't work. Secrecy orders backfired. Even their key escrow system fell flat on its face. And while their digital signature system did get adopted as a standard, almost nobody uses it.

      Quantum computing, meanwhile, can return the NSA to their former place of being able to plug in a wire and listen in on anyone they wanted. And, with the War on Terra still raging on, the political climate is a lot more sympathetic to their cause. All they have to do is mention September 11th and terrorists with strong crypto as much as possible and Congress will surrender faster than the French, because who wants to be seen as supporting terrorists?

      Let's face it: the general public won't see quantum computers for a long time -- if at all -- despite the technological advances. And quantum crypto will take longer. And then ITAR will get slapped in anyone's face who tries to get this beyond the US. It'll be like the '60s all over again.

      --
      Being a smartass is a much better thing than being the alternative.
  14. It can be both by Anonymous Coward · · Score: 0

    1)You can use quantum transmission to encrypt/ send and to know when your transmission has been intercepted..

    2)Quantum computers can be used to factor and solve the large computations needed to crack todays encryption codes in a reasonable time...

    What was so hard to understand?

  15. Scale by boffy_b · · Score: 1

    They use these rather than SI units(if there are such things for data) to give an idea of scale.

    I think most people reading that sentence will get the impression of it being "a bloody lot". It's more data than we can usefully express in our units. Like measuring the width of the galaxy in metres(the SI unit of distance)

    --
    Windows is only $500 if your time is worthless.
    1. Re:Scale by danila · · Score: 1

      Then it would make sense to give actual estimates, like 10^20-10^30 bytes per g (cm3) of storage AND simply say that this is much more than possible today.

      --
      Future Wiki -- If you don't think about the future, you cannot have one.
  16. Bremermann's limit? by Anonymous Coward · · Score: 1, Insightful

    Does this have the potential to make Bremermann's limit obsolete or did he have the forsight to take this into account?

    1. Re:Bremermann's limit? by Anonymous Coward · · Score: 0

      My exact thoughts about the issue!

      Yes, and what about Bremen's limit? Er, I mean, ahn, Bremermann's limit?

      Huh? Come on, don't say you didn't think about this important, uh, limit?

      (* pats foot on the ground with crossed arms *)

    2. Re:Bremermann's limit? by rasz · · Score: 1

      Does this have the potential to make Bremermann's limit obsolete or did he have the forsight to take this into account?
      Why ? Bremermanns limit doesnt apply when you power those things form the outside source (or apply if you count powersourse mass :P)

  17. Quantum terms by Decaff · · Score: 3, Interesting

    I wish physicists would be more cautious in their use of language.

    In the article it states: "The UCLA team succeeded in flipping a single electron spin upside down."

    Considering that the term 'spin' is just a metaphor for a quantum-mechanical property that has no equivalent in our everyday experience, it makes no sense to talk about 'flipping' it, or the spin being 'upside down'.

    Neat achievement though....

    1. Re:Quantum terms by Anonymous Coward · · Score: 0

      I wish physicists would be more cautious in their use of language.

      In the article it states: "The UCLA team succeeded in flipping a single electron spin upside down."

      Considering that the term 'spin' is just a metaphor for a quantum-mechanical property that has no equivalent in our everyday experience, it makes no sense to talk about 'flipping' it, or the spin being 'upside down'.

      Neat achievement though....


      Normally I'm all for people being pedantic, but in this case their language is perfectly appropriate. Spin is the intrinsic angular momentum of a particle (given in units of h-bar, if I remember P-chem correctly), and you can have spins of 0, 1/2, -1/2, 1, -1, 3/2, -3/2, and so on. Changing the spin of an electron from 1/2 to -1/2 is indeed flipping the spin, at least semantically. Maybe 'spin' wasn't the best idea for a name for this property, but hey, quarks come in colors and flavors! :)

    2. Re:Quantum terms by Anonymous Coward · · Score: 0

      Those bastards! Coining a term then using it differently than we do in normal English! They shouldn't even call it spin at all, since the electron is not actually "spinning." They should call it "the property that looks a lot like angular momentum, even though it technically isn't rotating, but we'll pretend it is because the math works out well that way and helps us make a lot of useful (and accurate) predictions" Doesn't really roll off the tongue though, does it? Bottom line is that it's a helpful way to visualize and understand a "property that has no equivalent in our everyday experience."

      Do you also object to quarks having color?

    3. Re:Quantum terms by Anonymous Coward · · Score: 0

      "I wish physicists would be more cautious in their use of language."

      We are. It's the physicist-press interface that mangles stuff.

      That's also where the crazy units come in... no physicist ever said "that's so much data you'd have to stack double decker buses full of CD-Rs from here to three times as far away as the Moon and back just to write down the number of bits using hexadecimal". But that stuff gets into press releases, because for some reason the media loves it.

    4. Re:Quantum terms by Ruie · · Score: 2, Interesting
      Actually this was pretty precise.

      You see electron spin space is a two dimensional complex space. It is tied to usual 3 dimensional real space via representation of SU(2) - so it is hard to say which direction corresponds to which.

      However, if one fixes a basis in usual space one can use it to fix a particular representation of SU(2).

      Furthermore, one of the basis vectors will have a particularly simple Pauli matrix corresponding to it - the direction of this vector is usually called "quantization axis".

      Often this vector corresponds to "z" axis. The "up" spin is then defined as (1,0) and the "down" spin is (0,1). So flipping the spin upside down is just switching components.

      Another justification for talking about "up" and "down" is that spin vectors are usually written as columns so there is an upper entry and the lower entry.

    5. Re:Quantum terms by Decaff · · Score: 1

      Spin is the intrinsic angular momentum of a particle

      In layman's terms: even Dirac hated the idea of angular momentum as electrons are either point charges, or small enough that the angular momentum would imply that the 'surface' of the electron would be travelling faster than light.

      More precisely: there is no 'spin' at all, simply a directional property of the particle.

      I don't mind the 'colors' and 'flavors' of quarks (I'm sure the physicists will be grateful for my approval), as these terms are silly enough that no-one assumes they are famililar physical properties.

    6. Re:Quantum terms by Decaff · · Score: 1

      They should call it "the property that looks a lot like angular momentum, even though it technically isn't rotating, but we'll pretend it is because the math works out well that way and helps us make a lot of useful (and accurate) predictions" Doesn't really roll off the tongue though, does it?

      Heh. Well why not pick some daft word that has no meaning, as was done with 'quark'?

      I don't mind the 'colors' and 'flavors' of quarks as these terms are silly enough that no-one assumes they are famililar physical properties.

    7. Re:Quantum terms by Decaff · · Score: 1

      You see electron spin space is a two dimensional complex space.

      I think this illustrates my point well! What mere mortals think of as 'spin' isn't two dimensional, complex, or a space.

      Why not follow the suggested of a learned old physicist (was it Rutherford?) and pick a word from poetry that has less meaning in 'the real world', like 'Gyre'?

    8. Re:Quantum terms by Decaff · · Score: 1

      That's also where the crazy units come in...


      There was an amusing series of articles in the UK New Scientist about daft units, like 'That was the weight of 12 blue whales' or 'the force of 5 steam trains'.

    9. Re:Quantum terms by Ruie · · Score: 1
      Perhaps I was not clear enough.

      Usual 3 dimensional spin is characterized by speed (revolutions per second) and the axis the object is spinning about.

      Flipping spin means reversing the axis - i.e. changing the direction of rotation.

      This is precisely what happens.

      Imagine a pool of water with a ball inside it. The ball is weighted so that it has the same specific weight as water - so it is inside it.

      Spin the ball so that the rotation axis is perpendicular to the still water. (How you do this is not relevant, but you could use an ultrasound controlled gyroscope inside the ball.)

      Now what is possible in quantum world is to reverse the direction of rotation while preserving the speed by sending waves in the water.

      The quantum nature manifests in "preserving the speed" part - quantization condition for electron spin requests that it is always at maximum possible rotation speed in some direction.

      The ability to reverse the spin is not quantum per se, but is due to the electric field using transversal waves (and its interaction with electron) versus waves in water (i.e. sound) being longitudinal waves.

    10. Re:Quantum terms by wass · · Score: 1
      Not true at all. Firstly, you confuse the physicists doing the research w/ the journalists that wrote the article. I didn't read the article, but I know enough quantum mechanics to explain what they meant.

      There's nothing wrong with 'flipping' the spin of the electorn. Spin is basically a quantized angular momentum that is "just there" in most particles (those without spin would be spin zero). Classically, angular momentum can come in many values. For example, a spinning top can spin in 2 directions (clockwise/counterclockwise) with rotational velocity in a continuum of acceptable values.

      An electron is different, it can only have one magnitude of spin, in each of two directions. This is because an electron is a spin-1/2 fermion, and only has two allowable spin 'states'. Nothing is allowed in between. These two spin states are known as eigenstates (because when represented in matrix form, the wavefunction is an eigenvector of the measurement operator, with the eigenvalue being the actual value of the spin). In any one basis, these eigenstates can be referred to "spin-up" and "spin-down". So if you measure the spin in any direction (say the z-axis direction), then the electron will be pointing with or opposite to the positive z axis. Subsequent spin measurements (assuming no other interactions w/ the electron) will ALWAYS yield the spin pointing in this direction. So the spin of an electron can be + or - hbar/2.

      The scientists in question have managed to 'flip' the spin using some interaction or other, so any subsequent measurements of the spin after the flip will point opposite to the original direction.

      Note - don't confuse 'spin' with the concept that the electron itself is really spinning, this notion isn't true. You're right that spin has no classical analog, but it acts exactly like a built-in angular momentum.

      --

      make world, not war

    11. Re:Quantum terms by Decaff · · Score: 2, Informative

      Must confess I am being pedantic here, so I may be annoying, but....

      Usual 3 dimensional spin is characterized by speed (revolutions per second) and the axis the object is spinning about.

      Yes, but with quantum mechanical particles, nothing is spinning. There is not one part of an electron that is rotating about another. (see my warning about 'pedantic' above!)

      Flipping spin means reversing the axis - i.e. changing the direction of rotation.

      But with quantum mechanical particles, there is no real 'direction' - its a relative property, and direction is meaningless when there are only limited states.

      Its a metaphor, an analogy, and that is all. We have absolutely no idea what is 'really' happening at the 'electron' level. All we have is some math that gives answers. I strongly believe that using terms like 'spin' gives a false impression of understanding. Eventually terms like 'spin' and 'orbit' are so frequently used they crowd out alternative metaphors.

    12. Re:Quantum terms by Ruie · · Score: 2, Interesting
      I guess we have different points of view them..

      Just for fun let me continue.. :)

      What do you mean by nothing is spinning ? What does it mean to be spinning ?

      I can tell when a ball spins because I can see it. But does Earth spin ? I can't see the rotation but I can infer it with tools.

      Do small pieces of matter (like dust) spin ? Maybe.

      Now it turns out when you look at very small pieces of matter (like particles) then the laws of nature we are accustomed to change. This is simply because we do not teach quantum mechanics in kindergarten.

      One that is aware of quantum mechanics see its manifestations on macro scale - they are just commonly perceived as separate phenomena (like electricity).

      Now classical rotation corresponds precisely to quantum spin.

      When you consider two quantum particles (with spins J1 and J2) as a single system the result is a tensor product of spins - so you get a direct sum of representations between |J1-J2| and |J1+J2|.

      When you have a lot of particles comprising a ball you can still describe it on a quantum mechanical level - it would be a direct sum of representations of SU(2) with numbers between 0 or 1/2 and N/2 (where N is the number of particles).

      The "usual" behaviour you are accustomed to happens because the particles have weakly interacting spins and are unordered.

      The quantum part can manifest in macroscopic situations, albeit in (so far) very restricted circumstance - for example quantum Hall effect.

      My point is that you can start at very small with quantum notion of spin and then as you increase the number of particles in your system you will gradually reach the situation where classical notions of spin are a *very* good approximation.

    13. Re:Quantum terms by Decaff · · Score: 1

      Ok... This is fun. You will have to bear in mind that although I am strong on the philosophy of QM, I'm very poor at the math, but here goes.

      What do you mean by nothing is spinning ? What does it mean to be spinning ?

      Spin is the act of rotating. A specific identifiable subset of an object undergoes a continuous displacement so as to change its angular position relative to other identifiable subsets.

      This is simply because we do not teach quantum mechanics in kindergarten.

      Heh. Sometimes I think it would be good if we tried - we might then get enough kids saying 'why?' and 'What does that mean?' to force us to question what we think.

      Now classical rotation corresponds precisely to quantum spin.

      From the Georgia State University Physics website: "The property called electron spin must be considered to be a quantum concept without detailed classical analogy".

      My point is that you can start at very small with quantum notion of spin and then as you increase the number of particles in your system you will gradually reach the situation where classical notions of spin are a *very* good approximation.

      And this is a very good point. I think its wrong, but I can't yet say why! If I think I can, I'll post some more.

    14. Re:Quantum terms by Ruie · · Score: 2, Interesting
      The "usual" behaviour you are accustomed to happens because the particles have weakly interacting spins and are unordered.

      Sorry, this is not right. Usual behaviour is due more to particles changing positions than to remnants of quantum behaviour.

      So your point would hold if we restrict ourselves to considering only spinning that is due to bodies rotating one around another.

      My point would hold if we allow idealization of solid body - i.e. an object with an intrinsic spin.

      For example, you could consider a ball as multitude of molecules changing positions around each other.

      Or we can consider it as idealized object (sphere) with an axis of rotation - I usually think of it this way. (So throwing a ball is composed of two parts - imparting linear movement and spinning the ball around with fingers. Note that usage of "spinning" as independent of movement.)

      Quantum spin is the right generalization of intrinsic spin at the quantum level.

    15. Re:Quantum terms by Ruie · · Score: 1
      From the Georgia State University Physics website: "The property called electron spin must be considered to be a quantum concept without detailed classical analogy"

      There is something called "geometrical quantization" which actually shows that quantum spin *is* the right analog of classical spin.

      The reason this is not mentioned is that it is easier to teach undergraduates how to calculate using spin rather than give understanding of it.

    16. Re:Quantum terms by Decaff · · Score: 1

      There is something called "geometrical quantization" which actually shows that quantum spin *is* the right analog of classical spin.

      I'm getting concerned that this is moving towards one of those 'I am wrong' situations.

      I'm getting out of my depth here, but I'm going to ask anyway...

      what do you mean by 'analog': Do you mean that electrons are actually rotating? Even Feynman had doubts about this.

      Analagous is not the same as 'same as'.

    17. Re:Quantum terms by trixillion · · Score: 2, Informative

      Saying that something is spinning in the classical sense imputes an angular momentum on the object. But the quantum of angular momentum has different units than the quantum of spin. Hence, quantum spin is fundamentally different from classical spin. And this is one of the rationales that has been argued for decades for why quantum spin should be given another name.

    18. Re:Quantum terms by Ruie · · Score: 1
      First of all there is an interpretation where you are right - see my other post (posted as a correction to the one we are discussing).

      Secondly, geometrical quantization is a mathematical construction (or description) of both quantum and classical systems in such a way that classical system is a limit of quantum one when h approaches 0 and the symmetry properties are preserved.

      It is called "geometrical" because geometry can be studied from the point of view of a set of points and a symmetry group acting on it - this approach was started by Klein about 100 years ago.

      I realize this all sounds very dry, but this is not the fault of this science - I am squeezing a somewhat large body of knowledge in a few sentences without pictures. It is really quite beautiful and does not require much calculation.

      Perhaps, I should make a toy game or something to play with.. Might be fun :)

    19. Re:Quantum terms by Decaff · · Score: 1

      It is really quite beautiful

      I totally agree. Far from being dry, I think it is astonishing and very deep.

    20. Re:Quantum terms by Anonymous Coward · · Score: 0

      angular momentum has different units than the quantum of spin

      wrong, same units.
      M L^2/T
      same as h
      If I'm wrong, tell us what the units are.
      When they same spin 1/2, it is shorthand for hbar/2.

    21. Re:Quantum terms by trixillion · · Score: 1

      Dammit... I retract what I said before, it was entirely wrong.

      That's what I get for copying someone elses argument I read a few days prior on another discussion board without first double checking to see if it was right. Sigh, the worst part is someone modded me up, which just goes to show...

  18. Imagine... by scr7b · · Score: 0

    A beowulf cluster of those!!

    1. Re:Imagine... by gnuLNX · · Score: 1

      Dork!

      --
      what?
  19. clarification by Rufus88 · · Score: 1

    He means:
    1 Parsec = 3.08568025 × 10^16 meters

  20. I had a Quantum hard drive before by gphinch · · Score: 5, Funny

    "With 100 transistors, each containing one of these electrons, you could have the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around," Yablonovitch said. "And why stop with 100 transistors?"

    I hope this drive lasts longer than the Quantumm Fireball I had.

    --
    in bed.
    1. Re:I had a Quantum hard drive before by mailtomomo · · Score: 0

      well, it will at least finish as a quantic fireball ...

    2. Re:I had a Quantum hard drive before by Anonymous Coward · · Score: 0

      I went through 4 quantum fireballs (3.2 gig) within the span of 2 years. Fucking horrible drives.. they'd either refuse to spin up or start clicking.

    3. Re:I had a Quantum hard drive before by bundaegi · · Score: 1

      I hope it'll be smaller than my quantum bigfoot too :-)

      --
      bundaegi is good for you
    4. Re:I had a Quantum hard drive before by meringuoid · · Score: 1
      I hope this drive lasts longer than the Quantumm Fireball I had.

      I don't know how long it will last, but at least I'm pretty certain of where it is.

      --
      Real Daleks don't climb stairs - they level the building.
  21. I'm also confident... by Anonymous Coward · · Score: 0

    Hong Wen Jiang admits, "...our initial theoretical calculations were very favorable, and gave us confidence to persevere."

    Whoa! I don't know what the hell you're talking about, but OK, since you admitted...

    I also admit that I'm confident that I'm perverse.

  22. why?? well, ... by J_Omega · · Score: 1

    it helps when looking for funding.

  23. WOW - big news... by teutonic_leech · · Score: 1

    Okay, I only skimmed the article (what's that STFA?) but this sounds like BIG news. If this holds true, existing hardware could be used for quantum computing - a very interesting possibility. Well, it's a long way from the science lab to everyday use, but I hope those guys can create something acutally usable throughout commercial computing.

    1. Re:WOW - big news... by NickFusion · · Score: 1

      Assuming your existing hardware is chilled to -400 farenheit, and equiped with a Maser.

      That was in the non-skimmy part of the article. It's pretty misleading, actually. A more accurate headline would have been, researchers flip the spin of an electron in a hunk of silicon that, coincidentaly, was located in an off-the-self transitor, using lots of expensive and complicated equipment.

      It's a good first step, though.

      --
      What were you expecting?
  24. Jamming communications? by Auxon · · Score: 1

    I just had a thought - not sure how you would do this, but if you made devices just to "look at" transmissions that were quantum encrypted, could you prevent the message from ever being received by the intended recipient?

    I know entanglement comes into play here, that is, the message doesn't actually have to travel, so you would have to target the devices that send and or receive the messages.

    Any thoughts?

    1. Re:Jamming communications? by Strenoth · · Score: 1

      you are confusing quantum computing and Quantum communication via antanglement when they talk about the cryptographic aspects, they mean using the quantum computer to encrypt the information isn such a way that only another quantum computer with the right codes is going to be able to decrypt it. Then you transmit the data normally. The entanglement technology does not need any sort of encryption, as only the particles involved can send/receive 'messages' between them.

      --

      "It takes a very long time to count to 2 in binary." ~'Fourlegged'

    2. Re:Jamming communications? by PitaBred · · Score: 1

      Sure, you could screw with one message. But then the transmitter/transmittee are on to you, and will move on to another place/tranmission setup that you're going to have to find and block yet again, and you still don't have their info.
      Entanglement may or may not come into play. Depends on what you're doing, because you can just use the quantum computer to do calculations and then send the info over more traditional means. This removes having to entangle many electrons, then put them in separate devices, etc.

    3. Re:Jamming communications? by Auxon · · Score: 1

      Good point! I did assume quantum communication was involved when it doesn't have to be. :-) And of course you're right about entanglement not requiring encryption. :-(

      However, it still leaves the question of how one might jam quantum communication in my mind. Is it even possible?

    4. Re:Jamming communications? by div_B · · Score: 1

      I just had a thought - not sure how you would do this, but if you made devices just to "look at" transmissions that were quantum encrypted, could you prevent the message from ever being received by the intended recipient?

      IIRC, the quantum crypto that was developed at NIST (the story was posted on /. some time ago I think) worked a little like this:

      The transmission is sent 1 photon at a time. The photons can have isospin(?) states [A],[B], or two superposition states, like [A]-[B] and [A]+[B] (ommiting the normalization constant). The crypto key is sent using the latter 2 states, corresponding to 1 and 0. Any measurement of the photons during their transit would collapse these states to either [A] or [B], hence at the receiving end it becomes immediately obvious that the key has been interacted with, and it is discarded. Hence multiple keys are sent (if necessary), until it is clear that the key has not been read in transit. With the key verified to be solid, the transmission of the message can begin.

      This doesn't prevent jamming by the method you propose of course, it only prevents reading of the message.

      Futhermore, the receiver will be observing ambient photons which could corrupt the message, so the receiver only makes note of those which arrive within pre-determined time windows to avoid this. (I guess that this would make it quite difficult to implement for comms between, say, ships and planes, as the transit time obviously depends on distance)

      The beam is highly directional, so I guess locating the beam would be the big hassle, but again the method is really about security from being read, not so much from being jammed.

  25. would you use your powers for good, or for awsome by machine+of+god · · Score: 1
    Why does every article about anything have to have the word "terrorist" in it, these days?


    Because if you don't immediately say that it (it, as in indefinite pronoun) is a weapon against the terrorists, someone moranic will cry that it will be used by the terrorists. And morans tend to stick together when it comes to irrational fear, so you don't want that.

  26. Ready for Doom 4! by Evil+Butters · · Score: 2, Interesting

    Cool... With one of these new quantum computers, I should be able to meet the minimum requirements for Doom 4! Now if only I could get my quantum video card to work...

    --
    Homer no function beer well without.
    1. Re:Ready for Doom 4! by Creepy+Crawler · · Score: 1

      Bah, you and your 2004 people!!

      Us back in 1994 have had "Quantum Harddrives" for So long now!! Whats taking YOU ALL SOO LONG?

      --
    2. Re:Ready for Doom 4! by Anonymous Coward · · Score: 0

      The key to getting your quantum video card to work properly is to stop observing the screen!

  27. How many? by Kozar_The_Malignant · · Score: 1

    >Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

    6.0 X 10^8 drives x 100 GB/drive x 15 x 10^9 years x 1.1 x 10^9 bytes/GB = 9.9 x 10^29 bytes. More or less. Definitely a BFN. This should be enough for most mp3 and pr0n collections. For reference, the number of electrons in the universe is estimated at 10^79, a larger BFN.
    --
    Some mornings it's hardly worth chewing through the restraints to get out of bed.
  28. Quantume Computing = Fraud by Louis+Savain · · Score: 0, Troll

    "UCLA is reporting progress on the quantum computing front by announcing success in controlling the spin of a single electron using an ordinary transistor."

    How does that constitute progress in quantum computing? I have been hearing about progress in quantum computing for a long time now. Sounds like a bunch of people who are afraid to lose their government grants and funding.

    I can't wait for the day when quantum computing is revealed for what it is, a silly hoax and a fraud.

    1. Re:Quantume Computing = Fraud by Anonymous Coward · · Score: 0

      Just because it won't be powering your new desktop PC in a few years doesn't mean it's a hoax. Quantum computing will be a great achievement for mathematics and physics. Just because you have no use for it does not mean it's a fraud.

    2. Re:Quantume Computing = Fraud by hugesmile · · Score: 1
      How does that constitute progress in quantum computing?

      It's a quantum leap, of course.

    3. Re:Quantume Computing = Fraud by DarkMan · · Score: 1

      This is a useful step forward, because it demonstrates a method for how to build a device from the familar silicon lithographic procedures.

      That's a big step forward, as it gives a method on how to construct these devices in mass production, and cheaply. That's one of the big hurdles before any actual use.

      Much of the work to date has been on trying to find such a method. Granted, there is more work to be done on such a substrate (e.g. How many qubits can you have in a single system?), but it's definitly progress.

      May I enquire as to why you think that quantum computing is a hoax?

  29. Toshiba produces... by Kozar_The_Malignant · · Score: 1

    600,000 1.8 inch drives per month according to a very quick google search. Total monthly production of all drives from all manufactureres will certainly exceed 1,000,000.

    --
    Some mornings it's hardly worth chewing through the restraints to get out of bed.
  30. Quantum voting? by patbob · · Score: 1, Funny
    Perhaps future elections will be held using secure quantum voting

    Republicans spin to the left, Liberals to the right and democrats just sit there? Or is it Republicans to the right, Democrats to the left and Liberals do nothing? Or it is...

    Dang! now I'm too dizzy to vote

    :-)

    --
    Welcome to the net of 1000 lies. Upgrades are scheduled soon that should bring us to the 10,000 lies mark.
    1. Re:Quantum voting? by otherniceman · · Score: 1

      The problem with Quantum voting is that you will change the result just my measuring it.

  31. Easy.. to get funding and stay out of jail by nurb432 · · Score: 1

    if you are for catching terrorists then you get government funding and avoid investigation.

    I you don't explicitly make the statement, you are instantly cast into suspicion..

    Welcome to this 'brave new world'... Exactly what Binny boy wanted..

    --
    ---- Booth was a patriot ----
    1. Re:Easy.. to get funding and stay out of jail by wfberg · · Score: 1
      if you are for catching terrorists then you get government funding and avoid investigation.

      On that note..
      • The NRA announces that "gun ownership prevents terrorism - we may never even know just how many lives were spared"
      • McDonalds announces "will the obese person sitting next to you shield you from the blast? Why the new McBiggerMac mitigates the threat of terrorism"
      • Michael Jackson claims "while sleeping with children I tell them stories about the nasty terrorists, and we have a good old Christian time. Why, I can be heard calling the Lord's name into the tiny hours"
      • Monica Lewinsky claims she was "protecting president Clinton's private parts against terrorists"
      • RIAA claims "competition and price cuts would bring morale-lifting music within reach of terrorists".
      • Bin Laden claims "twin towers were hotbed of an even worse terrorist organisation, which I got rid of at the CIA's request".

        and finally

      • Britney Spears defends mother running over papperazzi as "Oh my God, that guy was, like, totally jumping in front of the car, like, some sort of terrorist, completely, you know?"


      I'd include an "RIAA claims music piracy aids terrorism", but they actually do claim that..
      --
      SCO employee? Check out the bounty
  32. How long? by Savet+Hegar · · Score: 1

    The article mentions 10 years until it may be commercially feasible. But this probably means insanely expensive for all but huge corporations and government. How long are we looking at until something like this comes into daily lives like the PC?

    --
    Mod points are pointless when you browse at -1.
    1. Re:How long? by BiggerIsBetter · · Score: 1

      If it's as good as all that, it'll be unavailable for as long as they can keep it off the free market. I'd like to think you can't ban progress but this will be classified as munitions or something. Can't have the terrorists winning eh?

      --
      Forget thrust, drag, lift and weight. Airplanes fly because of money.
    2. Re:How long? by tehcyder · · Score: 1
      We'll probably only need 5 or 6 quantum computers in the whole world anyway.

      --
      To have a right to do a thing is not at all the same as to be right in doing it
  33. Whatever you do.... by Creepy+Crawler · · Score: 1

    DONT LOOK AT IT !!!

    It might go away...

    stupid lameness filter stupid lameness filter
    too many caps jackasses too many caps jackasses
    too bad you had to see this too bad you had to read this

    --
  34. Sliders by Anonymous Coward · · Score: 0

    i dont think we should be using this technology...imagine if we inadvertenly open a portal to a world full of cro-mags. they will then slide over here and enslave us with their highly evolved technology!

    if they do take our world and put us into re-education camps, i would certainly hope that they would play "Red Sector A" on the camp's PA all day.

    <prayer>oh jerry o'connell, forgive the scientists for they know not what they do. also, please protect us from the evil cro-mags.</prayer>
    amen.

  35. Hmm... by iamdrscience · · Score: 1

    Can anyone with more perspective on this, clue me in on what this really means? It seems like it would be a big breakthrough in quantum computing, making full on Quantum systems a possibility within a decade or so. Is this accurate, or are there still many more problems to solve that are more important than this one?

    1. Re:Hmm... by carnivore302 · · Score: 2, Informative

      First off: I am not an expert, just someone who watches this closely and has read a lot of books on the subject. (Hint: The fabric of reality and Quest for the Quantum computer are very good, not to difficult to read)

      In a sense, nothing has been achieved here that hasn't been achieved with other methods. These guys are strugling with just one quantum spin, which doesn't even make one qubit (you have to do more) where others like some researchers from IBM have already combined 4 qubits. Making just one qubit isn't all that difficult these days, but combining them in a way that they are still usable is increasingly difficult when the number of qubits increases. It's called the problem of decoherence.

      ...But: what is good about this is that it is being done with conventional approaches: an ordinary transistor. Now they can use everything that is known to transistors to proceed and make it better. (what is not so good is that they still need to do it at _very_ low temperatures.)

      --
      Please login to access my lawn
    2. Re:Hmm... by Anonymous Coward · · Score: 0

      So what's the difference between flipping spin and having a working qubit?

  36. Quantum computers are like women... by Fuzzums · · Score: 1

    Once you understand the state they're in the rules have changed ;)

    --
    Privacy is terrorism.
  37. Terrorists? by mikeg22 · · Score: 2, Insightful

    Oh, you mean the ones that use human couriers to relay messages? The ones that live in caves with no access to computers?

    No, this technology is not going to be used on terrorists. It is going to be used on a combination of normal people suspected of criminal activity (ie anyone who bothers to encrypt their communications) and actual hightech criminals.

    This technology will be effectively useless at stopping the terrorists we are worried about.

    1. Re:Terrorists? by Anonymous Coward · · Score: 0

      Score 2, Insightful? How about Score -10, Dumbass with a Tinfoil Hat?

      Guess what! Quantum cryptography has already been demonstrated. And guess what else comes with it? The impossibility of snooping on a quantum-encrypted communications channel without the receiving party knowing about it.

      So, if you're ultra-paranoid, guess what? You just send a pre-arranged random number of bursted messages containing "flapjack tinfoil" or other such nonsense, then followed by the real message if the receiver indicates the bursted messages have not been tampered with.

    2. Re:Terrorists? by Glock27 · · Score: 1
      Oh, you mean the ones that use human couriers to relay messages? The ones that live in caves with no access to computers?

      No, this technology is not going to be used on terrorists. It is going to be used on a combination of normal people suspected of criminal activity (ie anyone who bothers to encrypt their communications) and actual hightech criminals.

      This technology will be effectively useless at stopping the terrorists we are worried about.

      First of all, plenty of terrorists have access to technology and are no doubt interested in encryption. However, from what I just read at Wikipedia, it will take at least 1e12 entangled qubits to decrypt info encrypted with a 1000 bit key - much less 2048 bits. So even RSA encryption with decent key sizes seems quite safe.

      Any serious (read: military) crypto user will likely be using one time pads generated using a true random data source. That form of crypto has been mathematically proven to be unbreakable, if the pad isn't compromised (the pads should be distributed during a face-to-face meeting and securely guarded afterwords). Quantum doesn't help in decrypting one time pad encrypted data.

      Unfortunately, for e-commerce and such one time pads don't work since there is currently no secure way to distribute the pads. Untappable quantum comm channels could help with that problem...

      --
      Galileo: "The Earth revolves around the Sun!"
      Score: -1 100% Flamebait
    3. Re:Terrorists? by Glock27 · · Score: 1
      The impossibility of snooping on a quantum-encrypted communications channel without the receiving party knowing about it.

      To be fair, the correct expression is "quantum transmitted" not "quantum encrypted". You can send the message in cleartext if you're sure (on a bit-by-bit basis) that nothing has been intercepted.

      --
      Galileo: "The Earth revolves around the Sun!"
      Score: -1 100% Flamebait
    4. Re:Terrorists? by Big_Breaker · · Score: 1

      Presumably the system automatically sends "one time pads" until it determines that one has been received without eavesdropping. It then transmits the message encoded by that one-time pad. Unbreakable and very simple if the quantum detection is working.

    5. Re:Terrorists? by Glock27 · · Score: 1
      Presumably the system automatically sends "one time pads" until it determines that one has been received without eavesdropping. It then transmits the message encoded by that one-time pad. Unbreakable and very simple if the quantum detection is working.

      If you can provably detect eavesdropping, why bother with the pad? ;-)

      --
      Galileo: "The Earth revolves around the Sun!"
      Score: -1 100% Flamebait
  38. Don't hold your breath... by Dr.+Mu · · Score: 2, Interesting

    I Google-whacked 'quantum-computing Clear-Channel' and already got 63 hits.

    1. Re:Don't hold your breath... by DigiShaman · · Score: 1

      Pfftttt...please *sigh*

      If I Google-whack "Shampoo and ketchup" as is, I get 7 hits. Just because the search terms are found on the same page doesn't mean they are relevant to each other pertaining to a topic you're looking for.

      --
      Life is not for the lazy.
    2. Re:Don't hold your breath... by suffe · · Score: 1

      I shampoo with ketchup, you insensitive clod!

      --

      Karma: 2.71828182846 (Mostly due to small, fun pills)
  39. cliché by klubkid79 · · Score: 0

    Cue the obligatory quake III joke ..

  40. Re:Why does anyone believe this works... by Anonymous Coward · · Score: 0
    In other words, 100 quantum bits, all blathering by physicists aside, will do only what 100 regular bits do.
    Really? Then why does it require a Hilbert space containing 2^100 dimensions to completely describe the dynamics of this system based on the postulates of quantum mechanics? Surely if nature is keeping track of all this information there is the potential for us to harness this to gain a computational advantage.
  41. Re:Why does anyone believe this works... by Requiem+Aristos · · Score: 2, Insightful

    *SMACK*

    This would be an accurate description, only it's not.

    If you perform the double-slit experiment with twenty humans, a canon, and segments of brick walls, you don't wind up with an interference pattern. With electrons, you do. Also, factoring with quantum computers has been successfully performed, so we know it works.

    If it makes you feel better, it isn't just a matter of treating statistics as physical reality. It's more a matter of realizing that at certain small sizes, 'matter' isn't exactly matter. It's closer to energy, and has a wave behavior similar to energy. It just happens that measurable physical properties can only be said to exist when the wave function has 'collapsed'.

    (I expect some QM geek will want to correct my explanation, but it's certainly more accurate than your attempt. Happy trolling!)

  42. Nature article link by shadowmatter · · Score: 1

    The actual article to appear in Nature can be found here, which I found at the CNSI web page.

    I only wish that CNSI will complete construction before I graduate with my Master's in CS... Seems like it will be a great facility to do research on this sort of thing. Oh well, there's always CENS :)

    - shadowmatter

  43. boo. Article gets a thumbs down. No, the finger. by sacrilicious · · Score: 1, Interesting
    Quantum computing, which holds the promise of nearly unlimited processing power, secure communications and the ability to decode encrypted conversations by terrorists and others

    I was willing to forgive a little hype until the idiocy about terrorists. Decided maybe I was just cranky, then read:

    While flipping a single electron was difficult, detecting that they had actually done so proved even harder. "We couldn't tell whether it was flipping," Jiang said. "It was like looking for a needle in a haystack."

    Wow, I'm so illuminated by this "needle in a haystack" imagery. Before it I had no idea what was going on, but now it all seems so clear.

    This article blows. Can we get something better on slashdot please? Something that doesn't make me feel I'm being lumped in with people who need things drastically dumbed down, and/or rationalized in the name of "fighting terrorists"?

    --
    - First they ignore you, then they laugh at you, then ???, then profit.
  44. Re:Why does anyone believe this works... by GNT · · Score: 1

    Wrong analogy on the macroscopic level.

    Macroscopically if I do the double-slit experiment using REGULAR waves in a tub of water I DO get the result you would expect -- interference patterns. Noone would reasonably claim that there were any quantum states anywhere in that system. Yet shrink it down orders of magnitude and I'm told to discount everything about entities? No -- sorry.

    Also you need to understand that I am not discounting quantum theory -- I'm discounting a particular aspect of physical interpretation. And I am a QM geek (amateur) and I have stumped more than one physics professor on this particular point. (There is no satisfactory answer at present.)

    When all is said and done I bet that we will have quantum computation -- but it will just be ultrafast classical computation.

  45. Re:boo. Article gets a thumbs down. No, the finger by andy314159pi · · Score: 1

    I agree! This article is ridiculous.

    Anyhow, they seem to be missing the point. This isn't actually related to true quantum computing at all!

    Quantum computing would use states of atoms or molecules where the multiplicty would allow for many more states. In other words, switching spin states in a single electron gives you up or down (binary.) Switching states in an atom can give you different values depending on the particular atom. A typical small atom could give you 3 or 4 distinct states. This might let you do arithmetic in some base other than 2!

    We already have binary.

  46. Crackpot alert.... by douglips · · Score: 1

    I get a positive Crackpot Index just from this three line posting of his. And that's without even taking a shot at that "God gave us the secret to AI" website. I think my calculator might run out of digits...

    1. Re:Crackpot alert.... by Louis+Savain · · Score: 1

      I get a positive Crackpot Index just from this three line posting of his. And that's without even taking a shot at that "God gave us the secret to AI" website. I think my calculator might run out of digits...

      Your opinion matters to me because...

    2. Re:Crackpot alert.... by Anonymous Coward · · Score: 0

      The fact that his opinion of you doesn't matter to you matters to him because...

  47. Ya but... by DigiShaman · · Score: 0

    ...will it run Doom3 smoothly? Also, will it transform Duke Nukem Forever into Duke Nukem Now?

    "I put my mouth where my money is at"

    --
    Life is not for the lazy.
  48. WEBOROM - Write every, but only read one, memory by DumbSwede · · Score: 1
    From what I understand of quantum computing, the "implicit storage" would be storage used during the process of the calculation -- discrete data cannot be pumped in (beyond a classical 100 bit start state).

    Say you have an algorithm that needs to store all numbers from 0 to 2^100, then the algorithm excludes sets of them until arriving at an answer. The algorithm might truly need 2^100 words of 100 bits each to proceed on a classical computer, but on a quantum computer the calculation chugs along on our implicit storage until it arrives at an answer. As long as we never know the states of the implicit storage as the calculation unfolds it works, but we have at most 100 bits to read at the end of the calculation, and can only store 100 bits before the calculation. But this is the ultimate parallel computation, because each step in our calculations is working on all the numbers in our "implicit storage" at one time. The trick is getting the numbers to settle down and converge on one classical answer that can be read. See things like the Shor algorithm for composite number factoring.

    To fill our memory with every number before starting the calculation would take one hundred steps, each setting one bit in both on and off, but entangled with all other bits.

    Sorry, no unlimited pr0n storage for /. users. In effect, every JPEG is in memory, you just can't view any of them. A decided disadvantage for pr0n :-)

  49. Implicit Disinformation by reversible+physicist · · Score: 3, Interesting

    Quantum communication is already practical, and provides a secure way to communicate to replace factoring-based encryption, which quantum computation may one day make insecure. The hype in this article, though, is way over the top. 100 electron spins can only encode 100 classical bits. Not one bit extra. Yablonovitch is using a very sloppy way of talking about how hard it is to simulate 100 spins, and making it sound like he's talking about a way to store a lot of classical bits! His "implicit information storage" is nonsense. It's also worth mentioning that quantum computation is unlikely to speed up any computation you care about, unless you like to simulate quantum systems. Fast factoring is the "killer app" that got people excited about this field, but "terrorists" (and the rest of us) can just stop using factoring-based encryption.

    1. Re:Implicit Disinformation by Anonymous Coward · · Score: 0

      Unfortunately, while being essentially correct in your analysis, you missed elucidating as to precisely what he should have been talking about. Specifically, 100 electron spins represents a superposition of 2^100 states simultaneously; and with the proper algorithm/hardware, you can most likely determine which of those 2^100 possible "answers" is the correct one for your problem.

      So, if you have a pair of these 100-bit registers, in theory it would be possible to factor a number of up to 2^200 into its pair of prime factors.

    2. Re:Implicit Disinformation by Ithaca_nz · · Score: 1

      Yeah, not so much. Take a look at http://en.wikipedia.org/wiki/Qubit for something a little more accurate.

    3. Re:Implicit Disinformation by Anonymous Coward · · Score: 0

      You are wrong. 100 qubits represent much more information than 100 bits. It represent 2^100 bits. So... that's 2^97 bytes, 2^92 kB, 2^87 MB, 2^82 GB, and 2^77 tB, if I did my math correctly. So that's a whole freaking lot of information!

  50. Re:Why does anyone believe this works... by Anonymous Coward · · Score: 0
    When all is said and done I bet that we will have quantum computation -- but it will just be ultrafast classical computation.
    Nope. There is a lot more to it than this and it is obvious you don't really understand QM at all. What is your classical equivalent of the Bell state (non-normalised): \Ket{\psi} = \Ket{00} + \Ket{11} Each potential classical state of a quantum system exists as its own dimension in a complex Hilbert space (can be thought of as a generalisation of a real Euclidean space). The state outlined above is simply an amazing propery of QM (ie. entanglement). Try reading some research on quantum computing or some of the text books that exist on the subject. Quantum computing is about changing the complexity classes of algorithms not about increase clock speeds (eg. ultrafast classical computation).
  51. Re:Why does anyone believe this works... by GNT · · Score: 0

    Yep. So what? I never said it the 100 electrons couldn't represent the information.

    However, my 100 regular bits will quite nicely represent 2^100 states just as well. In fact my 256 megs of bits in my laptop can outstrip the possible states any day.

    What they (nor the q-computer) will ever do is represent 2^100 states all at the same time and perform some miraculous quantum collapse calculation.

  52. Re:Why does anyone believe this works... by GNT · · Score: 0

    Sigh. And then we can reformulate everything in a Clifford Algebra using classical axioms and get the same exact results but proving that QM computation is a chimera. So what! Use your head. At any moment in time the damnable 100 electrons are in a *particular* state -- and thus *cannot* be coerced into representing 2^100 states simultaneously.

    It's failure to see that an epistemological potential is not a physical reality and this traverses the whole of QM as it presently exists. Absurd conclusions of computing power all rest on the premise that I can hold two or more states in superimposition until I need to calculate. The only reason this nonsense exists is because of mis-interpretation of a particular aspect of QM.

    Wishing you well. You get the last word if you want it but I go to go back to my day job -- cancer research.

  53. Re:Why does anyone believe this works... by grvs · · Score: 1

    You said : "This idea that the electon is in some fuzzy position described by its probability is an epistemological statement -- not a physical one. The electron wave is somewhere 100% of the time in definite form." But a wave does not have a definite position because the energy is spread out over some region of space, so we can only give a proability of the wave being at a particular point at a particular time. The double slit experiment "proves" that electrons are waves, whilst the photoelectric effect "proves" that electrons are particles (and not waves). Classical mechanics is inadequate to describe these kinds of behaviour, hence the development of quantum mechanics. But what you find with quantum mechanics is that as the wave / particle size increases the results are identical with classical mechanics. A good example of this is the simple harmonic oscillator. It's all good stuff.

  54. Re:Why does anyone believe this works... by GNT · · Score: 0

    Well, I did say "area" in the sentence that followed.

    Again, 100 years of brainwashing and folks think you can't describe it "classically". Of course you can. It only requires that the impacting wave be smaller than the surface it's impacting and the area integrals associated to momentum/energy transfer do the rest. But that's if I wanted to be a real pain. You are fundamentally correct.

    I am attacking a very small part of QM -- something that does not invalidate for example, either quantization, wave packets etc. I'm attacking the notion that the particle is indefinite because given HUP I don't have an exact measurement. And downstream this leads to all sorts of nonsense, including the absurd notions of the power of QM computation.

  55. Not really so close to quantum computing by Muerte23 · · Score: 1

    What they did appears to be just flipping the spin (and detecting the flip) of a single electron.

    Creating and measuring the quantum state of a single particle is *not* new. Or that hard. The neat thing is that they did it with a commercial transistor.

    Oh, and some sort of fridge that goes to -400 F.

    The really hard part in quantum computing (as far as I can tell) is (a) creating and (b) maintaining a coherence between many particles.

    The problem is that useful coherences between particles are *very* easily destroyed. If you can hold coherent mixtures one the order of milliseconds, consider yourself lucky. Much less creating the state and performing the operations and then reading out the state...

    Muerte

  56. Got a Free Link? by Anonymous Coward · · Score: 0

    I'd love to read that, but I don't feel like paying for a subscription.

    1. Re:Got a Free Link? by shadowmatter · · Score: 1

      Huh. I was on campus when I found the link, and clicking on it brought me to the article. Now that I'm at home on my DSL connection, clicking on it brings me to a registration required page... Perhaps UCLA has a subscription to Nature Publishing Group, allowing me to view articles from on campus, verifying that I'm on campus by my IP address (they have one with O'Reilly, allowing me to peruse all of the O'Reilly Network Safari Bookshelf, which has come in handy more than once).

      Oh well... Leave me your e-mail addy and I'll see what I can do.

      - sm

  57. Name that profession by bigsteve@dstc · · Score: 2, Funny

    Do these researchers call themselves "quantum spin doctors" or just plain "quantum mechanics"?

  58. Awesome! A crackpot! by Muerte23 · · Score: 1

    I love it when people spew out their theories of why quantum mechanics is wrong - just because they can't understand it.

    When you say things like this you sound like the guys trying to sell "Zero Point Energy" and the like.

    Go read a book. For starters, I recommend Griffiths.

    Muerte

  59. I can see it now.... by teutonic_leech · · Score: 3, Funny

    Welcome to Windows Quantum 2006! We crash several ways at the same time!

  60. Intro to Quantum Computing by GogglesPisano · · Score: 3, Informative

    The following link may be helpful for those of us who are a little fuzzy on quantum computing: http://www.cs.caltech.edu/~westside/quantum-intro. html

    1. Re:Intro to Quantum Computing by Anonymous Coward · · Score: 1, Informative

      I highly recommend this "Introduction to Quantum Computing for Non-Physicists (36 pages). You should have some knowledge of linear algebra, though.

  61. QC Can't Break Existing Encryption Algorithms by Anonymous Coward · · Score: 0

    In fact, all you have to do is double the key size (in bits) on something like RSA to make it just as hard to break with a quantum computer as the original was with a regular computer. Quantum computing can only reduce the time required to perform the decription by a square root factor, but since the decription runtime is basically O(2^N), where N is the number of bits in the key, all you have to do is double N.

    1. Re:QC Can't Break Existing Encryption Algorithms by Christopher+Thomas · · Score: 1

      In fact, all you have to do is double the key size (in bits) on something like RSA to make it just as hard to break

      Bad example :).

      While this is true for any case where you're stuck doing a brute-force search, in the case of RSA there's a very, very fast algorithm for reversing the trapdoor function it uses (Shor's Algorithm, which factors the public key in far better than exponential time).

  62. Re:Why does anyone believe this works... by Hentai · · Score: 1

    I gave it a shot last week in my livejournal. Hope this helps.

    --
    -Hentai [in vita non pacem est]
  63. As I understand it by Julian+Morrison · · Score: 1

    ...mostly the government uses "one time pads". They're immune to any decryption because for an encrypted message of length N, any plaintext of length N is identically plausible. The way to break govenment encryption is to copy the pads, or subvert the guy who gets to read the plaintext.

    1. Re:As I understand it by AuMatar · · Score: 1

      I don't doubt they use them with their most secret operatives. But do you really think every piece of data on government computers uses a 1 time pad? That all of their military commands do? The problem with 1 time pads is they aren't very practicle- its very hard to get pads to people, and losing a single pad totally fucks up communication

      --
      I still have more fans than freaks. WTF is wrong with you people?
    2. Re:As I understand it by drinkypoo · · Score: 1

      It's hard to get pads to people? Step one put pad on some sort of media, step two send the pad to someone before they need it. If you are willing to spend the money you can get anything you can fit in, say, a truck between any two points on the globe in 72 hours or less. Given that the assorted militaries of the world are generally all too happy to spend great quantities of the populace's money, I suspect there's a lot more 1TP use than you think there is. This is not to say that all military communications use a one time pad, because you would have to have as much pad as you have data transfer, and that's not really practical, but anything that it's actually important to keep secret is almost certainly sent with a 1TP on almost every occasion. (There are always emergencies, but the military is pretty good at developing plans for contingencies, so I guess that one's a toss-up.)

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    3. Re:As I understand it by AuMatar · · Score: 1

      IF your person is a military commander on the field, or a secret agent infiltrating a foreign government, yes its hard to get it to him. In the first, you risk death of the messenger and loss of the pads. In the second, you risk blowing his cover. The reason public key encryption is used in general is that it is difficult to get keys to people, and that the courrier of the key is a weak link in the chain, either through force or through corruption.

      --
      I still have more fans than freaks. WTF is wrong with you people?
  64. Re:Why does anyone believe this works... by Anonymous Coward · · Score: 0

    I'm attacking...the absurd notions of the power of QM computation.

    shor's factoring algorithm has successfully been run on a quantum computer on the number 15, producing the correct prime factors (3 and 5). the computer used 7 qubits for the computation.

    google it...it had something to do with ibm research. i searched for quantum computer factor 15 and it turned up a few articles about it.

  65. schrodinger's Screen Saver by erice · · Score: 1

    Until you click the mouse and collapse the wave form, your Windows box will be crashed and not crashed simultaneously.

  66. Article is misleading by Anonymous Coward · · Score: 1, Informative

    As someone who has taken a course in quantum computing, I can tell you that this article has numerous inaccuracies and misleading statements. The section you highlight is an example. Many current encryption algorithms are based on the fact that it is difficult to factor large numbers (products of two primes). An algorithm for doing so efficiently has already been developed for quantum computers. So, as soon as we can build quantum computers (larger than a few qbits), today's toughest encryption algorithms will essentially become obsolete overnight.

    However, quantum computing also provides a secure means of communication. This means of communication is not secure because it uses some fancy cryptographic coding; it is "secure" because of the way it makes use of quantum physics, as opposed to classical physics. In essence, if two parties are communicating through a quantum channel using a secure quantum communication protocol, it is impossible for a third party to eavesdrop on the conversation. Note: I really mean impossible. Not just "difficult but maybe possible in the future with more processing power". I mean impossible as in doing so would require breaking the laws of physics (as we understand them today). An attempt to eavesdrop would (a) irrecoverably corrupt the data being communicated, and (b) be detectable by both parties (so they could halt communications as soon as the attempt to eavesdrop was detected). The probability that an eavesdropper would be successfull is vanishingly small. I.e., the eavesdropper would basically have to "guess" correctly for each bit of the communication.

    So, the statement the article makes is innane. Sure, existing encryption algorithms will be easily breakable with quantum computers. But because of that, no one who cares about security will use them anymore. What's to stop terrorists from using their own quantum computers and communication channels? It will be as impossible for the government to intercept their communications as it will be for terrorists to intercept the government's communications. The same goes for the average user - you and me.

    Our privacy may be "sacrificed" for a short transitionary period (in which some people have quantum computers but others still use classical encryption), but this will only last until quantum computers become commercially viable. Quantum computing is a big win for our privacy in the long run!

    1. Re:Article is misleading by Rich0 · · Score: 2, Interesting

      One problem - quantum crypto only works for direct hardware links. It does not allow for retransmission of photons. So, it is limited in range and generally to line of site (or whatever you can reach without reboosted fiber optics).

      There is no technology which would allow two distant parties (say 1000 miles apart) to use QC to secure their communication against any evesdropping. There is nothing to suggest that this technology will ever be developed.

      Now, with retransmission you could link two arbitrarily distant points. However, you could easiliy intercept the transmission without notice at the repeater. In fact, in most practical implementations, the repeaters are owned by a network provider, who of course would be complying with court orders, etc.

      So, QC will prevent cable tapping and stuff like that in the middle of nowhere. However, it will not prevent people with access to the satellites/network closets/etc from intercepting communications.

      For all practical purposes, that is no different from not having QC at all. How many communications are intercepted via cable-tapping these days? If you want to intercept something you either get a warrant for an ISP to install Carnivore, or you bribe somebody at the ISP (if you're not legit).

      So, QC will not lead to terrorist having secure lines of communication...

    2. Re:Article is misleading by Icekold · · Score: 1

      "Impossible for a third party to eavesdrop" is one thing, however what if the data that has been transmitted in such a way is required to be stored for a period of time greater than the time taken for the person to make use of it in one sitting; you will still need to encrypt the data on the local filesystem surely?

    3. Re:Article is misleading by Laebshade · · Score: 1

      I'm not a quantum mechanics buff, far from it, but I can analyze your comment. You contradict yourself a few times. First you say that it is impossible to eavesdrop on a conversation. Twice. Then you say essentially say that The probability that an eavesdropper would be successfull is vanishingly small.

      So which is it? Impossible or highly improbable?

    4. Re:Article is misleading by Anonymous Coward · · Score: 0

      Sorry about that. I guess I do contradict myself there. What I meant to say was that it is as hard for someone to eavesdrop on the conversation as it is for them to guess the contents of the conversation correctly. By definition, if the "eavesdropper" could do that, he wouldn't need to eavesdrop. (This is true for classical encryption methods too.) This probabilistic limitation is not due to anything like processing power (which we always seem to be improving); it is due to the laws of physics. Unlike current encryption methods, which are "weak" in the sense that they can be broken with enough computing power, no additional amount of processing power can raise the probability that eavesdropping can be performed successfully.

      From a statistician's point of view, nothing is "impossible": There is a finite probability that all of the particles in my body could spontaneously decide to tunnel through the nearest wall, but the probability of that happening is so ridiculously small that it can be considered impossible. You have to draw the line somewhere. For secure communications, if you have a communication method for which the probability of successfully eavesdropping is the same as the probability of correctly guessing the message, then it seems reasonable to say that it is "impossible" to eavesdrop on it.

    5. Re:Article is misleading by Anonymous Coward · · Score: 0

      Well, yes and no. As long as you could store the photons (or whatever particles you're using - photons are only one possibility) without letting them decohere, then they would still be secure. Of course, that means you wouldn't know what the data is either! ("Observing" or decoding the data causes/requires intentional decoherence of the particles.) If you want to read the data back, it means you are bringing the data back into the classical domain, and you have all of the traditional problems you mention.

      I'm not aware of any methods for securely storing quantum data over long periods, but then again there's a lot of stuff I'm not aware of, and new discoveries are being made in this feild all the time. However, one of the stumbling blocks in creating practical quantum computers is keeping particles from decohering for more than a few milliseconds - so storing it on a "quantum harddrive" is something that really can't do yet. The problem is that you have to prevent your particle from interacting with the surrounding environment. There was one method I heard about for isolating particles for use with quantum computation, etc. I think it was called an "ion trap", although I may be remembering that incorrectly. It involved a bunch of lasers and large magnetic fields. The physicists involved were able to keep a particle from decohering for a period of several days.

  67. OT: wrt to your sig by mysticgoat · · Score: 2, Funny

    Karma: pi (Mostly due to circular reasoning in posts).

    Sir:

    Your sig is irrational.

    Just thought you'd like to know that.

  68. Quantum computing at room temp? NOT!!! by mark-t · · Score: 1
    The problem is that with each extra degree that you raise the temperature above absolute zero, you increase the random kinetic energy level that is exhibited by the particles which exist in the environment. These extraneous vibrations will make it exponentially more difficult to detect individual electron spins. Detecting individual electron spin amidst the incredibly chaotic motion that is induced by heat at room temperature would be about as difficult as hearing the chirping of a single distant grasshopper while using a jackhammer.

    Now if they find some way to reduce brownian motion, or to possibly even predict it, then it may be possible to compensate for... but I won't hold my breath.

  69. Re:Why does anyone believe this works... by bhima · · Score: 1

    Actually rain prediction doesn't work like it sounds at all. 70% chance of rain really means that it will rain on 70% of the described area.

    --
    Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.
  70. Comment removed by account_deleted · · Score: 1

    Comment removed based on user account deletion

  71. Re:Why does anyone believe this works... by meringuoid · · Score: 1
    What they (nor the q-computer) will ever do is represent 2^100 states all at the same time and perform some miraculous quantum collapse calculation.

    Shame they already have, then. OK, so the current record for quantum computation is calculating that 15 = 3 x 5, but it's a start...

    --
    Real Daleks don't climb stairs - they level the building.
  72. Re:Quantum computing at room temp? NOT!!! by meringuoid · · Score: 1
    Now if they find some way to reduce brownian motion, or to possibly even predict it, then it may be possible to compensate for...

    Portable improbability drive, atomic vector plotter, nice hot cup of tea.

    --
    Real Daleks don't climb stairs - they level the building.
  73. Re:boo. Article gets a thumbs down. No, the finger by hplasm · · Score: 0

    Chill out! Maybe to " minus more than 400 degrees Fahrenheit." - perhaps? :->

    --
    ...and he grinned, like a fox eating shit out of a wire brush.
  74. hmmmm by Grizzlysmit · · Score: 1

    well thats got my head spinning

    --
    in my life God comes first.... but Linux is pretty high after that :-D
    Francis Smit
  75. iQantumPod.... by cheekyboy · · Score: 1

    just 2 trillion songs for storeage.
    pre installed with all songs made by all human history, $9.95.

    --
    Liberty freedom are no1, not dicks in suits.
  76. Manipulating *charge* of electrons? by Anonymous Coward · · Score: 0

    Look closely at the article - they claim that the manipulation (or, rather, detection) of single electron spin is the revolutionary thing, but they also mention manipulation charge of an electron, now that's revolutionary if you ask me.

    I somehow suspect the scientific value of this press release (even if the research would be worth something)...

  77. Transistors, Pah! by FraggedSquid · · Score: 1

    You want valves for a warmer sounding quantum computing experience.

    --
    You don't need a lab to make mud.
    1. Re:Transistors, Pah! by Anonymous Coward · · Score: 0

      funnier if you said 'tubes' not 'valves'

  78. Funny how the article is built up by thrill12 · · Score: 1

    Starting with
    Quantum computing, ... secure communications and the ability to decode encrypted conversations by terrorists and others,
    then continuing furtherup with
    When quantum computing becomes a reality, the government may be able to use it to eavesdrop on terrorists and quickly break sophisticated secret codes.

    What a brave new world we have, when every new technology we discover is immediately primed towards a most 'noble cause' as allowing the government to invade on (amongst a minority of others) innocent people's privacy.
    Get your thoughts of that subject and start thinking about some of the following uses instead:
    - cancer treatment research
    - exploration of physics laws
    - assistance in discovering stronger materials
    - intelligent systems

    And I bet there is much more good use out there.

    --
    Slashdot: stuff for news, nerds that matter, matter for news, stuff that nerd
  79. transistors by chrisranjana.com · · Score: 0

    Oh the good old days of transistors and radio valves !

    --
    Chris ,
    Php Programmers.
  80. Spin doctorig elections... by ArsenneLupin · · Score: 1
    Quoting from the article:

    Perhaps future elections will be held using secure quantum voting.

    "We've manipulated one spin,"

    Hehe, how inadvertedly appropriate ;-) Just lets home that the world's wave-function doesn't collapse into a nucular holocaust.

    But anyways, right now, it looks as if scientists are trying to produce an electrion with spin=0 instead.

    Oh, the date, you say? Then look at this link!

  81. "Quantum voting" by tooloftheoligarchy · · Score: 2, Funny

    (From the article): Perhaps future elections will be held using secure quantum voting.

    Gives new meaning to the term "spin doctor".

  82. is there more? by Anonymous Coward · · Score: 0

    well if this quantum state thing is so difficul to
    achive, maybe there's a reason for this?
    i mean in classical computing, electrons aren't
    "really" the information, they're just simulating
    logic.
    (i think it is possible to implement a logical
    gate with a dam and some channels ...)
    in quantum computing, i take it, the electrons ARE
    the information. so we ARE using something that
    exists as is in the univers and maybe the universe
    isn't to happy about this?

    maybe there's is way more to gain from "real"
    electrons, like, think free energy?

  83. Re:Why does anyone believe this works... by Glock27 · · Score: 1
    Actually rain prediction doesn't work like it sounds at all. 70% chance of rain really means that it will rain on 70% of the described area.

    "Actually" that's not right. It means there's a 70% chance of rain falling somewhere in the area of interest during the 24 hours in question.

    There are many possible different interpretations, I actually got curious enough to look it up a few weeks ago. Sorry I'm not motivated enough to find a link for you... ;-)

    --
    Galileo: "The Earth revolves around the Sun!"
    Score: -1 100% Flamebait
  84. Doom 4? by Laebshade · · Score: 1

    Don't you mean Doom 3? Yeah, I know since the specs were released Doom 3 requirement jokes aren't funny anymore.

  85. YOU are misleading by infolib · · Score: 1

    However, quantum computing also provides a secure means of communication.

    Not really. The fact is that these two technologies are totally independent - it is quite possible to achieve one of them while being a long way from the other.

    For instance, quantum encryption (non-eavesdroppable comm) is already on the high-end commercial market. Quantum computing (quick factorization) is not. IBM factored 15 into 3 and 5 with a quantum computer, but their approach doesn't scale. Lots of labs are working on this.

    Now, many people see quantum encryption as the logical answer to quantum computing. It is, but not a very practical answer. Remember that you have to have a direct physical connection to use quantum encryption. Alternatively you should build a chain of quantum links, and then trust all routers, switches etc. along the way. Not very useful for Internet traffic.

    --
    Any sufficiently advanced libertarian utopia is indistinguishable from government.
    1. Re:YOU are misleading by Anonymous Coward · · Score: 0

      Remember that you have to have a direct physical connection to use quantum encryption. Alternatively you should build a chain of quantum links, and then trust all routers, switches etc. along the way. Not very useful for Internet traffic.

      This is not exactly correct. By using quantum teleportation, you do not need to have a direct physical connection at the that communication is happening. If the two parties already have pairs of entangled particles, then communication can still be done securely by transmitting only classical information. (If each party has one half of an entangled pair, then it is possible to "teleport" a photon by sending only classical information. This is why quantum teleportation doesn't allow faster-than-light communication: Although it "looks" like the particle gets teleported "instantly", it is necessary to send a message from one party to the other in order to do the job, and that message is still limited by the speed of light.)

      This means that the two parties would need to have previously exchanged a bunch of entangled pairs, which does require a physical connection. In other words, before starting their communication, the two parties would have to be in physical contact. This does not reduce security, however: the entangled pairs convey no information themselves, and "eavesdropping" on them would be pointless - it would just dis-entangle them. Entangled pairs can be thought of as a kind of "resource" which makes all sorts of weird quantum stuff possible.

      You're right, though. This probably wouldn't be useful for things like Internet radio. It would be more appropriate for setting up a secure communication channel between two parties that often want to be able to communicate securely. (Maybe in the future, ISP providers will work by sending halves of EPR pairs to customers. Then "bandwidth" would be measured in numbers of EPR pairs per second, or something like that.)

  86. A prelude to shared computing? by Savet+Hegar · · Score: 1

    If this is the case, would this make shared computing almost certain at some future point? Or do I misunderstand the technology?

    --
    Mod points are pointless when you browse at -1.
  87. huh? by AyeRoxor! · · Score: 1

    It's been a long road for the researchers involved, and even the project lead, Hong Wen Jiang admits, "...our initial theoretical calculations were very favorable, and gave us confidence to persevere."

    So, it's been a long journey, and no-one less than the project leader is forced to admit that... he didn't think the project would fail?

    What a tough thing to admit.

    /three cheers for weird phrasing

  88. Re:Quantum computing at room temp? NOT!!! by rasz · · Score: 1

    Now if they find some way to reduce brownian motion, or to possibly even predict it

    Chaos theory anyone ? or even better - "PI"

  89. The world does not exist by sirangusthefuzz · · Score: 1

    With the advancement of Quantum Computing we must call into question our own existence. There is a philisophical theory that exists, which states:

    A race of intelligent lifeforms reached the technological advancement of quantum computing and we are living in a simulated world running on a quantum computer the size of a laptop. When we finally achieve quantum computing would it not be interesting to simulate our entire evolution in extreme detail. If we are able to accurately simulate the universe then it is feasible that it has already been done and we are the simulation.

  90. Storage size in bytes? by bootmonkey · · Score: 1

    "Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes." Lets see..... Universe age 11,200,000,000 x 30,000,000 hard drives = 336,000,000,000,000,000 336,000,000,000,000,000/8 = 42,000,000,000,000,000 bytes so thats 42 Exabytes THAT'S ALL!? Man ...................

    1. Re:Storage size in bytes? by Anonymous Coward · · Score: 0

      He mentioned the amount of INFORMATION in all HD's made this year. Not the number of HD's. So it's much, much more the 42 hexabytes.

  91. Re:Quantum computing at room temp? NOT!!! by Anonymous Coward · · Score: 0

    A atomic vector plotter would come in very handy when demodulalizing the qubit superstates. unfortunly there is no such thing as a atomic vector plotter (yet)

  92. Re:Awesome! A crackpot! by Anonymous Coward · · Score: 0

    i recommend Perry Rhodan

  93. Re:Secure communications? Entanglement... by Anonymous Coward · · Score: 0

    Of course, data "transmission" via entangled electrons would be instantaneous and not subject to interception...

  94. Re:Storage size in bytes? 42 like he said by Anonymous Coward · · Score: 0

    42

  95. About Time by schmoo.me · · Score: 1

    ...I hope this ends up with a machine fast enough to work with.