Actually it's the other way around: You CANNOT build 'quantum' repeaters, and switches/routers would be pretty hard without being able to read the stream(reading it would change the data inside the stream, which is a big no-no).
This means it's a point-to-point solution without any intermediaries. Only the receiver's hardware can read the quantum channel. So no, the quantum channel is not vulnerable to snooping at all.
Remember that only the key is exchange on the quantum channel, the rest is done over normal classical channels.
As is anything else around us. I mean, you cannot hold that argument only against QKD, as you'd have to say that to EVERY new discoveries or invention:
"You know that toaster? Maybe if we discover something new in science it could stop working!"
However, it is a good addendum to add, as I hate that argument, it feels too overconfident for my taste.
Well, I won't say you're a troll, but probably missinformed.
Quantum cryptography has a cool name, but in practice, it sucks, at least its current implementations.
Ok, that's right. But it sucks not because it's flawed, but because it's too slow to communicate with yet(well, to create the key actually).
It's not end-to-end by design (you can't have a direct fiber to everyone you want to communicate with these days, after all), and so it's easily regulated.
More current implementations use 'wireless' quantum channels in open air, so it isn't restricted to fiber only. I agree that you won't have consumer implementation before at least 8-10 years, but if a big corporation or government wants to use it, they will be able to in the near future.
It's expensive.
Sure. Is there a new technology that isn't expensive? Is that incentive enough to stop developing new ideas and such? No.
It doesn't solve key management problems, and the installations that have been publicly described so far are extremely vulnerable to man-in-the-middle attacks.
WOAH! Until then it was ok, just some argumentation problems, but this is pure outright missinformation. I don't know where you read that, I'd like to know.
First, Quantum Key Distribution is there to SOLVE key management problems related to one-time pad methods. The first and foremost goal of quantum encryption is to remove the logistic problems of one-time pad. So, you are wayyy off on this one.
Second, QKD is unconditionally secure, and that includes man-in-the-middle. I doubt current implementation are "extremely vulnerable" against that attack, unless you have some proof to show, I'd be interested to know.
If I believed in conspiracy theories, I'd say that the NSA is luring the EU towards unavailable and untested quantum cryptography, and away from commercially available, tested, reliable and rather secure conventional crypto products. Actually, the quantum crypto recommendation (whether it's contained in some EU documents or not) is the result of a pretty slick PR (and lobbying) campaign.
Well, I can't argue about tin-foiled hat arguments, hehe. The problem with conventional crypto methods is that they are breakable in the absolute, and the Echelon program is certainly the one who is able to achieve this feat. QKD isn't. This is the main point in favor of QKD, especially when you want to protect yourself against Echelon.
The thing is, in the classical world, only the one-time pad is provably secure. All other form of encryption revolve around the fact that it's too hard to factorize prime numbers. So, echelon is rumoured to have enough power and intelligence to be able to decrypt most form of current encryption , which renders our current encryption model obselete. There comes Quantum Key Distribution, which allows to use one-time pad with much less logistical problems and NO way to intercept the key. This means the method as a whole is uncoditionally secure.
Sorry to disapoint you: you are wrong. Let me explain a bit.
First, it's not Quantum Intrusion Detection. It's Quantum Key Distribution. It allows 2 people to exchange a randomly generated key as long as the message, used in a one-time pad scheme.
They trick is that the exchange of the key is unconditionally secure. Not only does it tells you when part of the key is intercepted, it also 'aborts'. The only thing an eavesdropper can do is to prevent you from communicating. If the communication is successful, then no one eavesdropped or got enough information on the key to jeopardize the exchange.
This is the beauty of it.
So no, it's not Quantum Encryption per see, as the encryption is done in classical term using one-time pad method, but it's not Quantum Intrusion Detection either. It's a very ingenious mix of both quantum and classical method which results in an unconditionally secure method of encryption.
And, I'd have to talk about Gilles Brassard(he teaches at the "Universite de Montreal" where I study). about stripping his degrees, as he's the co-inventor of quantum encryption and computing in general. I think he'd laugh but agree that Quantum Encryption is the resulting solution, not the means. "Encryption using quantum principles" might be more revelent, but quite longuer. Quantum Key Distribution is my personal favorite.
While I'm sure it sounds well and good to a legislator in the EU when they hear about supposedly "unbreakable" quantum cryptography, this sounds like another case of someone mistaking it for some kind of panacea for eavesdropping.
Well, this is just wrong. QKD(Quantum Key Ditribution) isn't 'supposedly' unbreakable, it is unconditionally secure and as been proved so many times. I hate to use this argument, but it is true to some extend: you'd have to break the rules of nature to break it.
However to say that, you have ignore the fact that science changes and evolves(and the laws of nature to some extend), quantum mechanics is a recent science and changed the playing field a lot, so we could discover something new like that, but then you cannot hold that against QKD, as it affects everything.
The real truth of the matter is that, of course, quantum crypto is only effective at the line level, i.e. as soon as it leaves the medium it was transmitted on, the cryptographic effect is lost. So it's entirely impractical for anything but a point to point connection.
So are EVERY other encryption methods. As soon as you decrypt the message, it's in the clear. What's the big deal?
BTW, you DO NOT send the messages over a 'quantum line', like you seem to hint at. You send all communications over classical channels and use a classical algorithm: one-time pad. The quantum channel is only used to exchanged a randomly generated key that is as long as the message. This is why it's uncoditionally secure: the mix of the strengths of both classical and quantum mechanics in one solution.
Also, I don't think people realize how strong cryptography is today. There are cryptographic methods available to the public at large (such as RC5 and PGP) that are proven to require more computing power than is theoretically possible in the universe. Not just more computing power than is possible with current hardware, but the theoretical limits of computation given the entire resources of the universe. So really, it seems that a lot of ignorance is at play here, and I would hope someone clueful in the EU informs their EU government before they go off and waste a whole lot of taxpayer money on such a foolish project.
But then again, they ARE breakable, where QKD isn't. A quantum computer could decrypt those messages in a fraction of time that a classical computer takes. There are many great and much faster algorithms used for primality testing in quantum computing.
I do not believe increasing the size of the encryption key is the way to go in the long run. Doing this means you know there is a problem, but just try to patch it and patch it again.
Nope, quantum entanglement isn't used in Quantum Encryption.
As a matter of fact, you probably couldn't communicate reliably with quantum-based communication, much less quantum encryption or using quantum entanglement to communicate securely, as you hinted.
Also, I want to add a note that I personally think it shouldn't be called Quantum Encryption but "Quantum Key Distribution"(QKD), as it is a much better name for it. They use the property of quantum mechanics to exchange a key which allows them to use the one-time pad method to encrypt the message, which MUCH less logistical problems, and no way to intercept the key. The encryption algorithm is purely classical and not quantum-based. This makes QKD in such a way that it allows 2 people to communicate without anyone being able to intercept the keys with any known attacks/methods(timed, man-in-the-middle, etc.), they can only prevent them from exchanging a key and thus communicating(which in some case might be worst tho).
Well,for one-time pad, the logistics is the hardest as you've stated. However, if implemented correctly and as soon as it becomes more viable, quantum key distribution QKD will alleviate all problems of key distribution. However, I don't see it used mainstream in the next 10yrs, but it could be used by the govt and things like that in less than 10yrs IMHO.
With no way for someone to eavesdrop the key or without showing any vulnerabilty to known types of attack(timed, man-in-the-middle, etc.), it's going to be a pretty secure one-time pad implementation, with MUCH less logistic problem(albeit there still are some limitation, so probably forget about mainstream before a long while). It's still said to be unconditionally secure, and AFAIK, it's gonna take something else we didn't discover/thought of yet to be able to conclude otherwise.
Well, the other point of view, and Deutch counter point is also a God theory:
Since no real photon can interfere with itself, lets say an imaginary one does.
Kinda like God Theory to me. Also, who knows enough about our universe to be saying what is IN our universe orin others for that matter? No one. So, thus there shouldn't be science.
I believe your counterpoint is not valid.
I'm personally torn a bit between both as I believe we're missing a crucial information to adequatly interprete it.
I know that. But my proposed method of defeating it does. Their detector wouldn't know the photon my system emitted was entangled with one that I controlled.
This is a clever idea, but it doesn't help breaking the key. See below.
I'm not re-emitting anything. I'm determining the quantum state of their photon. Their detector does that, so mine can too. I'm changing the quantum state of my own photon. They're transmitter does that, so mine can too.
Like I said, clever idea, but it won't help. As soon as either you or the receiver 'reads' the qubit, the qubit of the other has his value set. But this doesn't change anything, because the key distribution DOES NOT send the key, just random bits from the sender, and both side 'marks' equal bits. So, if you entangle a photon with one of your own, the 2 entangle photon have 'random' value. Sure, both will be read as opposite 'values' when as soon as one of them is read, but you cannot do the following:
For example you receive |0>. You cannot be able to entangle it AND keep the |0> photon and get an entangled |1> on your side. The entangle photon will become something like a|00> + a|11> maybe. HOWEVER, QKD doesn't use qubits in the strict sense. For example, we could say 0 is a vertical spin "|" and 1 is a diagonal spin "/". We're not really working on qubits. Entanglement would change those spins. |00> != |0>
So when Bob will receive the entangled photon, it will NOT be the original photon, so in the end, he will interpret it wrong, and either reject the photon because it's not equal to his own, or think it's equal to his own, in which case he's either wrong or right. So when they will verify a sample of the key, they will detect the error if their is one, with pretty high accuracy, OR, they will think it's ok and their communication will fail. You cannot entangle all the photons going thru and get a good reading at the end, the communication will most cetainly fail, because entanglement doesn't recreate the original value in either the entangled photon. So, in the end, you can only prevent 2 people from communicating, you cannot intercept the key. I'm not going to post a complete proof.
One thing people forget is that QKD is a mix of QC and Classical Computing. This is the strength. It prevents QC attacks and Classical Attacks.
The only difference is, I'm changing the state of a photon that causes a quantum state change in an entangled photon, but I don't see a problem with that. In fact, while I'm not a quantum physicist, what I propose seems only slightly more difficult than what they're already doing. Breaking encryption is almost always more difficult than encrypting and decrypting. That's the only purpose of encryption - to make it more difficult, not completely impossible as the researchers seem to be claiming.
The problem is that, EVEN in classical science, the one-time pad method with a key as long as the message IS totally secure. It's proven. However, logistically, it's nearly impossible to use, and someone could 'steal' the one-time pad and get all the keys, so that's why we use algorithms and such to have 'good' encryption.
QKD is NOT a new encryption algorithm. It's the one-time pad method, WITHOUT the logistical problems(although it's kinda slow right now) and WITHOUT having to worry about the key being intercepted. QKD CANNOT be intercepted, with complete mathematic proof that were double checked often. We proved it as strongly as we proved other theorems and such in mathematics. Whether you agree or thrust mathematics is another thing.
Third, it doesn't work 'based on a short window of time'.
Yes, it does. The linked article specifically mentioned this. Actually, I think it might have been a link from the linked article. The critical time window was the method they use to determine which arriving photon was the key photon, as opposed to a photon emitted by the sun.
Wrong. You should get a textbox or take a course on quantum computing and encryption.
You cannot act as a repeater without changing the quantum data. It is IMPOSSIBLE to recreate accurately a qubit, so retransmiting exactly the same data is impossible. This is not classical science.
QKD (Quantum key distribution) is UNCONDITIONALLY SECURE. It CANNOT be intercepted with a man-in-the-middle scheme, or ANY other scheme for that matter.
The worst that can happen, is that you can prevent both parties from communicating. However, you cannot eavesdrop a successful communication.
The Quantum Man In The Middle To prevent the man-in-the-middle attack where a photon is intercepted and an identical photon is transmitted in its place, the sender and receiver rely on a very tight window in time. Any photons received outside that window are rejected. If you want to grab the quantum secured key, why not put a receiver in the middle that emits a quantum entangled photon? You intercept the sender's photon, and once you know its state you can change the state of the captured photon so its entangled twin has the same quantum state as the intercepted photon, and arrives at the correct time. You essentially use quantum entanglement to change the state of the imposter photon while it's in transit.
That's not how it works. First, quantum encryption doesn't rely on entanglement. Second, you CANNOT reproduce quantum information, so you cannot intercept it and re-emit it without changing the value. Third, it doesn't work 'based on a short window of time'. Quantum Key Distribution (QKD) is proven unconditionally secure. You cannot intercept the key, only prevent both parties from exchanging a key.
Quantum Brute Force Quantum computing is emerging almost as fast as "quantum cryptography" (actually "quantum tamper resistant key transmission"). In the near future a good quantum computer will be fast enough to quickly break today's strong encryption. This is the same old game of making sure encryption is just strong enough that commercial users can't crack it but governments can. It's a moving target. Make your own VERY secure encryption algorithm that jumps fifty years down the path of Moore's Law. Add 32 bits to your key and you're secure. That'll piss off your government. So will tying up several hours on their massive supercomputers to learn that you used your favorite commercial encryption algorithm to send your grandmother's cream candy recipe to an internet cafe in South Africa. I'd never do that, but I'd be very tempted to send The Constitution and The Bill of Rights.
You are right. However, quantum encryption ISN'T based on an algorithm. It's based on the one-time pad principle. If you generate a key that is as long as the message, and use it only once, it cannot be decrypted. You even use XOR to encrypt the message! And since the key distribution is totally secure, you have a totally secure encryption, not using any algorithm.
So, yes, quantum computing can break classical encryption algorithm easily, but it cannot decrypt a message encrypted with a one-time pad method, and a key as long as the message.
Wrong. Quantum cryptographic is provably TOTALLY secure(UNCONDITIONALLY SECURITY is the term used). The complete proof was done 2-3 years ago I believe, under the guidance of Gilles Brassard from the University of Montreal, who is the forefather of quantum computing. This is IIRC.
The proof is BASED on the fact that we cannot measure the state of a photon accurately, or even send exactly one photon. Remember, quantum encryption is only about key exchange, not sending the actual message over quantum channels.
And, I'm pretty sure we CAN send one photon accuratly now. Here's a quote form a 2002 article:
"Quantum encryption isn't new, but the problem with current methods is that they rely on single-photon receivers and transmitters. This means sending encrypted information is slow.
"They have to run their technology on a single-photon regime -- they can only transmit data one photon at a time," said Prem Kumar, professor of electrical and computer engineering at Northwestern and a leader of the quantum encryption project."
Now, the current article said that they speeded that up greatly, which is awesome.
The actual way it works is the following. (simplified to bits instead of qubits for the sake of simplicity, and I probably forgot some details here and there)
1) Alice generates a random number of bits.
2) Bob generates a random number of bits.
3) Alice sends bits sequence to Bob, and Bob reads them, noting the place where both are equal.
4) Bob tells Alice every place the bits are equal, over a CLASSICAL channel.
NOTE: This is the part that needs understanding. The proof that you cannot evesdrop is as follow:
4a)If the bit that Alice sent is the same as Bob, but was intercepted at 3), Bob will see it as different, so the bit will be discarded. 4b)If the bit that Alice sent isn't the same as Bob, but was intercepted at 3), Bob will register it as the same and will try to use it. See 5).
5) Alice and Bob test a couple of bits to check the integrity, over a CLASSICAL channel. This is the critical part, you need a big enough sample to prove that it is equal, but not too big so that the attacker knows too much about the key. The sample needed isn't actually that big. If you have one bit wrong, it was eavesdropped or corrupted along the way. If you do not detect any wrong bit, it means that the attacker doesn't have much information about the key, if at all. If 4b) happened, this part will detect those 'bad bits' with accuracy.
6) Alice encrypt the message with the key and sends it to Bob as if it wasa one-time pad.
If you want more info about quantum computing, see a introduction by one of the forefathers of quantum computing, Gilles Brassard, who I had the joy to have a class with.
"The quantum key exchange method is totally secure."
That would be true. If you can generate a key as long as the message you want to send, and the key exchange is totally secure, it means that no one can decrypt the message (one-time pad).
The encrypted message is never sent over quantum channels, so it could be intercepted, but it would be impossible to decrypt it, as the key is totally secure and is as long as the message itself.
The beauty is that you cannot intercept the key in this way(keylogger, spywares, etc.) That's because key exchange in quantum encryption is proven TOTALLY secure. First because the keylogger won't log anything(the key isn't typed), and a spyware or eavesdropper will interfer with the key exchange and either prevent the key exchange, or will end up having useless information that isn't used in the creation of the key.
However, yes, you could read the actual message before it is encrypted(check over your coworker's shoulder, etc). But then if you can do that, whatever the encryption used, you'll always be able to see the message, so encryption is not a solution.
Wrong. We are talking one-time pad here. The key is going to be as long as the data needed to be sent.
Quantum Encryption allows you to exchange a key in TOTAL security. Not just theorically, total security(this is the strongest possible). No one can eavesdrop the key. If they do, they will, at most(if they eavesdrop every 'packet'), prevent you from exchanging a key, in which case you can try again until you succed. If you succeed in exchanging a key, the eavesdropper CANNOT know, due to the algorithm and quantum properties, any information about the key.
Then, with a key generated that is as long as the data needed to be sent, it is already proven secure. That's the one-time pad proof.
So, if the one-time method pad is proven secure(which it is), and there is NO way to know the key(totally secure, remember), it means that quantum encryption is secure beyond all doubts.
With faster quantum bandwith, it means that it is slowly becomes easier and easier to do quantum encryption. This is a GOOD THING, as you do not have to rely on unsecure algorithms like 3DES, etc.
Mod parent up, that's exactly what I was going to write. Good job corvi.
The long story short is that, quantum encryption is used to create a key. It is proven, due to the quantum properties and the algo that corvi posted above, that the key CANNOT be intercepted. At worst, it will fail, until you're able to suceed in creating a key.
So, a spy can ONLY prevent you from exchanging a key with someone, he can never intercept the actual key. So he's not really as much a spy as a roadblock.
The problem being that this is not possible. Wage rates in India etc. are LOW compared to the western world. There is no way to go and work in Idia and save and come back to the west.
Well the idea is to _not_ come back. Stay in India. A 20-30K pay in india nets you a big house, a good car, etc. Less money gives you a higher life standard in India than in the US for example. You need to be a doctor or have a 100k+ income to have about the same standard of living in California for example.
The whole reason India is a high-growth area is there are reasonably well educated people that will work cheap. That's the whole reason US firms are outsourcing there, you can pay an Indian much less to do the same job than a comparably educated American.
Exactly. For them, they do not work cheap, the pay is really good actually.
So basically, your idea is bullshit.
Dunno, your arguments haven't proved anything, you actually didn't have much in terms of arguments. This doesn't prove or disprove anything tho.
Personally, I am against globalism and outsourcing on principles. However, economically, globalism helps everyone and increases the standard of living everywhere. Countries will need to specialize, and everyone will be a winner. However, this is globally, not individually, so yes, people will pay in the immediate future, because the specialization of their country might contradict their talents. That's what I am against it, and why I dislike economics/capitalism/etc. It's just amoral(not immoral), and I believe that since we live in communities, everything should be about morals(however everyone needs to define the term for themselves), especially the basis of our society: economics. No one should be forced(economically) to do something he doesn't like because he doesn't have a choice(due to the economy).
But without copyrights the GPL means nothing, everything would be in the public domain and thus the GPL cannot be enforced. The GPL is just a distribution license of copyrighted work. It's not because we call it copyleft that it isn't based on copyright.
But on the other hand, there isn't a km square of land that doesn't have ants, they existed thousands of years before us(we are but infant compared to them in term of age) and they are the only animal that can resist nuclear and biological weapons. We use science because we have weak bodies. Maybe their science isn't as advance as our because they are physically strong and work as a collective, so science is less important for them?
Oh, and you know that they do use chemical weapons, and some species are known to make and use weapons similar to catapults? They seem to use military tactics and adapts pretty fast, probably because of their collectivness due to their mode of communication.
So lets not dismiss them right away.
Re:Mathematics not universal?
on
The Golden Ratio
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· Score: 4, Interesting
Different civilizations use different math systems, but they're all related by basic concepts. Addition is addition, no matter how you write it down. Any two math systems can be translated back and forth.
WRONG.
Let's take 2 valid mathematical system: Classical Mathematics(CM) and Intuitionist Mathematics(IM).
One thing that is provable in one system might not be provable in the other, or could even be wrong.
For example, if we take the mathematical subset of Logic we have Classical Logic(CL) and Intuitionist Logic(IT).
In CL, NOT(NOT(P)) |= P. It is easy to see why. Same with A OR NOT(A).
However, for IL, something is only True if and only if it's provable.
So, NOT(NOT(P)) |= P becomes: If there is no proof that a proof of P is impossible, then P is provable. This is invalid. The absence of a counter-example doesn't prove the fact.
So we see that NOT(NOT(P)) doesn't imply that there is a proof of P.
Same for A or NOT(A), because we cannot assume that it's always possible to either prove A or it's negation.
One of the fundamental differences in the 2 math systems is that, in IM, it requires a constructive proof.
So, in IM, you cannot prove something like that:
Proof (...) Case1: A = X then (...) Case2: A != X then (...) (...)
This doesn't work, for the same reason as A or NOT A, you need to prove one or another, so you need to prove that A = X or that A != X.
Ok, the point is, these are 2 working, acceptable and valid mathematical systems, but they cannot be swapped, because CM != IM.
So, NO, two math systems CANNOT be translated back and forth. This is but the tip of the iceberg.
Slashdot Mirror
Actually it's the other way around: You CANNOT build 'quantum' repeaters, and switches/routers would be pretty hard without being able to read the stream(reading it would change the data inside the stream, which is a big no-no).
This means it's a point-to-point solution without any intermediaries. Only the receiver's hardware can read the quantum channel. So no, the quantum channel is not vulnerable to snooping at all.
Remember that only the key is exchange on the quantum channel, the rest is done over normal classical channels.
What is this "Quantum Intrusion Detection" you speak of?
The only quantum method in cryptography is Quantum Key Distribution. As the name states, it has a key.
However, no one but the recipient can have the key, if someone eavesdrop, the exchange is aborted.
As is anything else around us. I mean, you cannot hold that argument only against QKD, as you'd have to say that to EVERY new discoveries or invention:
"You know that toaster? Maybe if we discover something new in science it could stop working!"
However, it is a good addendum to add, as I hate that argument, it feels too overconfident for my taste.
Well, I won't say you're a troll, but probably missinformed.
Quantum cryptography has a cool name, but in practice, it sucks, at least its current implementations.
Ok, that's right. But it sucks not because it's flawed, but because it's too slow to communicate with yet(well, to create the key actually).
It's not end-to-end by design (you can't have a direct fiber to everyone you want to communicate with these days, after all), and so it's easily regulated.
More current implementations use 'wireless' quantum channels in open air, so it isn't restricted to fiber only. I agree that you won't have consumer implementation before at least 8-10 years, but if a big corporation or government wants to use it, they will be able to in the near future.
It's expensive.
Sure. Is there a new technology that isn't expensive? Is that incentive enough to stop developing new ideas and such? No.
It doesn't solve key management problems, and the installations that have been publicly described so far are extremely vulnerable to man-in-the-middle attacks.
WOAH! Until then it was ok, just some argumentation problems, but this is pure outright missinformation. I don't know where you read that, I'd like to know.
First, Quantum Key Distribution is there to SOLVE key management problems related to one-time pad methods. The first and foremost goal of quantum encryption is to remove the logistic problems of one-time pad. So, you are wayyy off on this one.
Second, QKD is unconditionally secure, and that includes man-in-the-middle. I doubt current implementation are "extremely vulnerable" against that attack, unless you have some proof to show, I'd be interested to know.
If I believed in conspiracy theories, I'd say that the NSA is luring the EU towards unavailable and untested quantum cryptography, and away from commercially available, tested, reliable and rather secure conventional crypto products. Actually, the quantum crypto recommendation (whether it's contained in some EU documents or not) is the result of a pretty slick PR (and lobbying) campaign.
Well, I can't argue about tin-foiled hat arguments, hehe. The problem with conventional crypto methods is that they are breakable in the absolute, and the Echelon program is certainly the one who is able to achieve this feat. QKD isn't. This is the main point in favor of QKD, especially when you want to protect yourself against Echelon.
True. He means that one 'pad' is generated dynamically and exchange between both parties before each message is sent.
The thing is, in the classical world, only the one-time pad is provably secure. All other form of encryption revolve around the fact that it's too hard to factorize prime numbers. So, echelon is rumoured to have enough power and intelligence to be able to decrypt most form of current encryption , which renders our current encryption model obselete. There comes Quantum Key Distribution, which allows to use one-time pad with much less logistical problems and NO way to intercept the key. This means the method as a whole is uncoditionally secure.
Sorry to disapoint you: you are wrong. Let me explain a bit.
First, it's not Quantum Intrusion Detection. It's Quantum Key Distribution. It allows 2 people to exchange a randomly generated key as long as the message, used in a one-time pad scheme.
They trick is that the exchange of the key is unconditionally secure. Not only does it tells you when part of the key is intercepted, it also 'aborts'. The only thing an eavesdropper can do is to prevent you from communicating. If the communication is successful, then no one eavesdropped or got enough information on the key to jeopardize the exchange.
This is the beauty of it.
So no, it's not Quantum Encryption per see, as the encryption is done in classical term using one-time pad method, but it's not Quantum Intrusion Detection either. It's a very ingenious mix of both quantum and classical method which results in an unconditionally secure method of encryption.
And, I'd have to talk about Gilles Brassard(he teaches at the "Universite de Montreal" where I study). about stripping his degrees, as he's the co-inventor of quantum encryption and computing in general. I think he'd laugh but agree that Quantum Encryption is the resulting solution, not the means. "Encryption using quantum principles" might be more revelent, but quite longuer. Quantum Key Distribution is my personal favorite.
While I'm sure it sounds well and good to a legislator in the EU when they hear about supposedly "unbreakable" quantum cryptography, this sounds like another case of someone mistaking it for some kind of panacea for eavesdropping.
Well, this is just wrong. QKD(Quantum Key Ditribution) isn't 'supposedly' unbreakable, it is unconditionally secure and as been proved so many times. I hate to use this argument, but it is true to some extend: you'd have to break the rules of nature to break it.
However to say that, you have ignore the fact that science changes and evolves(and the laws of nature to some extend), quantum mechanics is a recent science and changed the playing field a lot, so we could discover something new like that, but then you cannot hold that against QKD, as it affects everything.
The real truth of the matter is that, of course, quantum crypto is only effective at the line level, i.e. as soon as it leaves the medium it was transmitted on, the cryptographic effect is lost. So it's entirely impractical for anything but a point to point connection.
So are EVERY other encryption methods. As soon as you decrypt the message, it's in the clear. What's the big deal?
BTW, you DO NOT send the messages over a 'quantum line', like you seem to hint at. You send all communications over classical channels and use a classical algorithm: one-time pad. The quantum channel is only used to exchanged a randomly generated key that is as long as the message. This is why it's uncoditionally secure: the mix of the strengths of both classical and quantum mechanics in one solution.
Also, I don't think people realize how strong cryptography is today. There are cryptographic methods available to the public at large (such as RC5 and PGP) that are proven to require more computing power than is theoretically possible in the universe. Not just more computing power than is possible with current hardware, but the theoretical limits of computation given the entire resources of the universe. So really, it seems that a lot of ignorance is at play here, and I would hope someone clueful in the EU informs their EU government before they go off and waste a whole lot of taxpayer money on such a foolish project.
But then again, they ARE breakable, where QKD isn't. A quantum computer could decrypt those messages in a fraction of time that a classical computer takes. There are many great and much faster algorithms used for primality testing in quantum computing.
I do not believe increasing the size of the encryption key is the way to go in the long run. Doing this means you know there is a problem, but just try to patch it and patch it again.
Nope, quantum entanglement isn't used in Quantum Encryption.
As a matter of fact, you probably couldn't communicate reliably with quantum-based communication, much less quantum encryption or using quantum entanglement to communicate securely, as you hinted.
Also, I want to add a note that I personally think it shouldn't be called Quantum Encryption but "Quantum Key Distribution"(QKD), as it is a much better name for it. They use the property of quantum mechanics to exchange a key which allows them to use the one-time pad method to encrypt the message, which MUCH less logistical problems, and no way to intercept the key. The encryption algorithm is purely classical and not quantum-based. This makes QKD in such a way that it allows 2 people to communicate without anyone being able to intercept the keys with any known attacks/methods(timed, man-in-the-middle, etc.), they can only prevent them from exchanging a key and thus communicating(which in some case might be worst tho).
Well,for one-time pad, the logistics is the hardest as you've stated. However, if implemented correctly and as soon as it becomes more viable, quantum key distribution QKD will alleviate all problems of key distribution. However, I don't see it used mainstream in the next 10yrs, but it could be used by the govt and things like that in less than 10yrs IMHO.
With no way for someone to eavesdrop the key or without showing any vulnerabilty to known types of attack(timed, man-in-the-middle, etc.), it's going to be a pretty secure one-time pad implementation, with MUCH less logistic problem(albeit there still are some limitation, so probably forget about mainstream before a long while). It's still said to be unconditionally secure, and AFAIK, it's gonna take something else we didn't discover/thought of yet to be able to conclude otherwise.
Well, the other point of view, and Deutch counter point is also a God theory:
Since no real photon can interfere with itself, lets say an imaginary one does.
Kinda like God Theory to me. Also, who knows enough about our universe to be saying what is IN our universe orin others for that matter? No one. So, thus there shouldn't be science.
I believe your counterpoint is not valid.
I'm personally torn a bit between both as I believe we're missing a crucial information to adequatly interprete it.
I know that. But my proposed method of defeating it does. Their detector wouldn't know the photon my system emitted was entangled with one that I controlled.
This is a clever idea, but it doesn't help breaking the key. See below.
I'm not re-emitting anything. I'm determining the quantum state of their photon. Their detector does that, so mine can too. I'm changing the quantum state of my own photon. They're transmitter does that, so mine can too.
Like I said, clever idea, but it won't help. As soon as either you or the receiver 'reads' the qubit, the qubit of the other has his value set. But this doesn't change anything, because the key distribution DOES NOT send the key, just random bits from the sender, and both side 'marks' equal bits. So, if you entangle a photon with one of your own, the 2 entangle photon have 'random' value. Sure, both will be read as opposite 'values' when as soon as one of them is read, but you cannot do the following:
For example you receive |0>. You cannot be able to entangle it AND keep the |0> photon and get an entangled |1> on your side. The entangle photon will become something like a|00> + a|11> maybe. HOWEVER, QKD doesn't use qubits in the strict sense. For example, we could say 0 is a vertical spin "|" and 1 is a diagonal spin "/". We're not really working on qubits. Entanglement would change those spins. |00> != |0>
So when Bob will receive the entangled photon, it will NOT be the original photon, so in the end, he will interpret it wrong, and either reject the photon because it's not equal to his own, or think it's equal to his own, in which case he's either wrong or right. So when they will verify a sample of the key, they will detect the error if their is one, with pretty high accuracy, OR, they will think it's ok and their communication will fail. You cannot entangle all the photons going thru and get a good reading at the end, the communication will most cetainly fail, because entanglement doesn't recreate the original value in either the entangled photon. So, in the end, you can only prevent 2 people from communicating, you cannot intercept the key. I'm not going to post a complete proof.
One thing people forget is that QKD is a mix of QC and Classical Computing. This is the strength. It prevents QC attacks and Classical Attacks.
The only difference is, I'm changing the state of a photon that causes a quantum state change in an entangled photon, but I don't see a problem with that. In fact, while I'm not a quantum physicist, what I propose seems only slightly more difficult than what they're already doing. Breaking encryption is almost always more difficult than encrypting and decrypting. That's the only purpose of encryption - to make it more difficult, not completely impossible as the researchers seem to be claiming.
The problem is that, EVEN in classical science, the one-time pad method with a key as long as the message IS totally secure. It's proven. However, logistically, it's nearly impossible to use, and someone could 'steal' the one-time pad and get all the keys, so that's why we use algorithms and such to have 'good' encryption.
QKD is NOT a new encryption algorithm. It's the one-time pad method, WITHOUT the logistical problems(although it's kinda slow right now) and WITHOUT having to worry about the key being intercepted. QKD CANNOT be intercepted, with complete mathematic proof that were double checked often. We proved it as strongly as we proved other theorems and such in mathematics. Whether you agree or thrust mathematics is another thing.
Third, it doesn't work 'based on a short window of time'.
Yes, it does. The linked article specifically mentioned this. Actually, I think it might have been a link from the linked article. The critical time window was the method they use to determine which arriving photon was the key photon, as opposed to a photon emitted by the sun.
Oh yeah, for reading purpose, yes, photons are
Wrong. You should get a textbox or take a course on quantum computing and encryption.
You cannot act as a repeater without changing the quantum data. It is IMPOSSIBLE to recreate accurately a qubit, so retransmiting exactly the same data is impossible. This is not classical science.
QKD (Quantum key distribution) is UNCONDITIONALLY SECURE. It CANNOT be intercepted with a man-in-the-middle scheme, or ANY other scheme for that matter.
The worst that can happen, is that you can prevent both parties from communicating. However, you cannot eavesdrop a successful communication.
Hacker Rule #1: Everything can be hacked.
The Quantum Man In The Middle
To prevent the man-in-the-middle attack where a photon is intercepted and an identical photon is transmitted in its place, the sender and receiver rely on a very tight window in time. Any photons received outside that window are rejected. If you want to grab the quantum secured key, why not put a receiver in the middle that emits a quantum entangled photon? You intercept the sender's photon, and once you know its state you can change the state of the captured photon so its entangled twin has the same quantum state as the intercepted photon, and arrives at the correct time. You essentially use quantum entanglement to change the state of the imposter photon while it's in transit.
That's not how it works. First, quantum encryption doesn't rely on entanglement. Second, you CANNOT reproduce quantum information, so you cannot intercept it and re-emit it without changing the value. Third, it doesn't work 'based on a short window of time'. Quantum Key Distribution (QKD) is proven unconditionally secure. You cannot intercept the key, only prevent both parties from exchanging a key.
Quantum Brute Force
Quantum computing is emerging almost as fast as "quantum cryptography" (actually "quantum tamper resistant key transmission"). In the near future a good quantum computer will be fast enough to quickly break today's strong encryption. This is the same old game of making sure encryption is just strong enough that commercial users can't crack it but governments can. It's a moving target. Make your own VERY secure encryption algorithm that jumps fifty years down the path of Moore's Law. Add 32 bits to your key and you're secure. That'll piss off your government. So will tying up several hours on their massive supercomputers to learn that you used your favorite commercial encryption algorithm to send your grandmother's cream candy recipe to an internet cafe in South Africa. I'd never do that, but I'd be very tempted to send The Constitution and The Bill of Rights.
You are right. However, quantum encryption ISN'T based on an algorithm. It's based on the one-time pad principle. If you generate a key that is as long as the message, and use it only once, it cannot be decrypted. You even use XOR to encrypt the message! And since the key distribution is totally secure, you have a totally secure encryption, not using any algorithm.
So, yes, quantum computing can break classical encryption algorithm easily, but it cannot decrypt a message encrypted with a one-time pad method, and a key as long as the message.
Wrong. Quantum cryptographic is provably TOTALLY secure(UNCONDITIONALLY SECURITY is the term used). The complete proof was done 2-3 years ago I believe, under the guidance of Gilles Brassard from the University of Montreal, who is the forefather of quantum computing. This is IIRC.
The proof is BASED on the fact that we cannot measure the state of a photon accurately, or even send exactly one photon. Remember, quantum encryption is only about key exchange, not sending the actual message over quantum channels.
And, I'm pretty sure we CAN send one photon accuratly now. Here's a quote form a 2002 article:
"Quantum encryption isn't new, but the problem with current methods is that they rely on single-photon receivers and transmitters. This means sending encrypted information is slow.
"They have to run their technology on a single-photon regime -- they can only transmit data one photon at a time," said Prem Kumar, professor of electrical and computer engineering at Northwestern and a leader of the quantum encryption project."
Now, the current article said that they speeded that up greatly, which is awesome.
The actual way it works is the following. (simplified to bits instead of qubits for the sake of simplicity, and I probably forgot some details here and there)
l
1) Alice generates a random number of bits.
2) Bob generates a random number of bits.
3) Alice sends bits sequence to Bob, and Bob reads them, noting the place where both are equal.
4) Bob tells Alice every place the bits are equal, over a CLASSICAL channel.
NOTE:
This is the part that needs understanding. The proof that you cannot evesdrop is as follow:
4a)If the bit that Alice sent is the same as Bob, but was intercepted at 3), Bob will see it as different, so the bit will be discarded.
4b)If the bit that Alice sent isn't the same as Bob, but was intercepted at 3), Bob will register it as the same and will try to use it. See 5).
5) Alice and Bob test a couple of bits to check the integrity, over a CLASSICAL channel. This is the critical part, you need a big enough sample to prove that it is equal, but not too big so that the attacker knows too much about the key. The sample needed isn't actually that big. If you have one bit wrong, it was eavesdropped or corrupted along the way. If you do not detect any wrong bit, it means that the attacker doesn't have much information about the key, if at all. If 4b) happened, this part will detect those 'bad bits' with accuracy.
6) Alice encrypt the message with the key and sends it to Bob as if it wasa one-time pad.
If you want more info about quantum computing, see a introduction by one of the forefathers of quantum computing, Gilles Brassard, who I had the joy to have a class with.
http://www.iro.umontreal.ca/~brassard/SSGRR.htm
The submitter is wrong, he should have said:
"The quantum key exchange mothod is always safe."
Actually, an even stronger claim could be:
"The quantum key exchange method is totally secure."
That would be true. If you can generate a key as long as the message you want to send, and the key exchange is totally secure, it means that no one can decrypt the message (one-time pad).
The encrypted message is never sent over quantum channels, so it could be intercepted, but it would be impossible to decrypt it, as the key is totally secure and is as long as the message itself.
The beauty is that you cannot intercept the key in this way(keylogger, spywares, etc.) That's because key exchange in quantum encryption is proven TOTALLY secure. First because the keylogger won't log anything(the key isn't typed), and a spyware or eavesdropper will interfer with the key exchange and either prevent the key exchange, or will end up having useless information that isn't used in the creation of the key.
However, yes, you could read the actual message before it is encrypted(check over your coworker's shoulder, etc). But then if you can do that, whatever the encryption used, you'll always be able to see the message, so encryption is not a solution.
Encryption as a whole is never a silverbullet =)
Wrong. We are talking one-time pad here. The key is going to be as long as the data needed to be sent.
Quantum Encryption allows you to exchange a key in TOTAL security. Not just theorically, total security(this is the strongest possible). No one can eavesdrop the key. If they do, they will, at most(if they eavesdrop every 'packet'), prevent you from exchanging a key, in which case you can try again until you succed. If you succeed in exchanging a key, the eavesdropper CANNOT know, due to the algorithm and quantum properties, any information about the key.
Then, with a key generated that is as long as the data needed to be sent, it is already proven secure. That's the one-time pad proof.
So, if the one-time method pad is proven secure(which it is), and there is NO way to know the key(totally secure, remember), it means that quantum encryption is secure beyond all doubts.
With faster quantum bandwith, it means that it is slowly becomes easier and easier to do quantum encryption. This is a GOOD THING, as you do not have to rely on unsecure algorithms like 3DES, etc.
Mod parent up, that's exactly what I was going to write. Good job corvi.
The long story short is that, quantum encryption is used to create a key. It is proven, due to the quantum properties and the algo that corvi posted above, that the key CANNOT be intercepted. At worst, it will fail, until you're able to suceed in creating a key.
So, a spy can ONLY prevent you from exchanging a key with someone, he can never intercept the actual key. So he's not really as much a spy as a roadblock.
The problem being that this is not possible. Wage rates in India etc. are LOW compared to the western world. There is no way to go and work in Idia and save and come back to the west.
Well the idea is to _not_ come back. Stay in India. A 20-30K pay in india nets you a big house, a good car, etc. Less money gives you a higher life standard in India than in the US for example. You need to be a doctor or have a 100k+ income to have about the same standard of living in California for example.
The whole reason India is a high-growth area is there are reasonably well educated people that will work cheap. That's the whole reason US firms are outsourcing there, you can pay an Indian much less to do the same job than a comparably educated American.
Exactly. For them, they do not work cheap, the pay is really good actually.
So basically, your idea is bullshit.
Dunno, your arguments haven't proved anything, you actually didn't have much in terms of arguments. This doesn't prove or disprove anything tho.
Personally, I am against globalism and outsourcing on principles. However, economically, globalism helps everyone and increases the standard of living everywhere. Countries will need to specialize, and everyone will be a winner. However, this is globally, not individually, so yes, people will pay in the immediate future, because the specialization of their country might contradict their talents. That's what I am against it, and why I dislike economics/capitalism/etc. It's just amoral(not immoral), and I believe that since we live in communities, everything should be about morals(however everyone needs to define the term for themselves), especially the basis of our society: economics. No one should be forced(economically) to do something he doesn't like because he doesn't have a choice(due to the economy).
But that's another topic.
Or badgers?
But without copyrights the GPL means nothing, everything would be in the public domain and thus the GPL cannot be enforced. The GPL is just a distribution license of copyrighted work. It's not because we call it copyleft that it isn't based on copyright.
But on the other hand, there isn't a km square of land that doesn't have ants, they existed thousands of years before us(we are but infant compared to them in term of age) and they are the only animal that can resist nuclear and biological weapons. We use science because we have weak bodies. Maybe their science isn't as advance as our because they are physically strong and work as a collective, so science is less important for them?
Oh, and you know that they do use chemical weapons, and some species are known to make and use weapons similar to catapults? They seem to use military tactics and adapts pretty fast, probably because of their collectivness due to their mode of communication.
So lets not dismiss them right away.
Different civilizations use different math systems, but they're all related by basic concepts. Addition is addition, no matter how you write it down. Any two math systems can be translated back and forth.
WRONG.
Let's take 2 valid mathematical system: Classical Mathematics(CM) and Intuitionist Mathematics(IM).
One thing that is provable in one system might not be provable in the other, or could even be wrong.
For example, if we take the mathematical subset of Logic we have Classical Logic(CL) and Intuitionist Logic(IT).
In CL, NOT(NOT(P)) |= P.
It is easy to see why.
Same with A OR NOT(A).
However, for IL, something is only True if and only if it's provable.
So, NOT(NOT(P)) |= P becomes:
If there is no proof that a proof of P is impossible, then P is provable. This is invalid. The absence of a counter-example doesn't prove the fact.
So we see that NOT(NOT(P)) doesn't imply that there is a proof of P.
Same for A or NOT(A), because we cannot assume that it's always possible to either prove A or it's negation.
One of the fundamental differences in the 2 math systems is that, in IM, it requires a constructive proof.
So, in IM, you cannot prove something like that:
Proof
(...)
Case1: A = X then (...)
Case2: A != X then (...)
(...)
This doesn't work, for the same reason as A or NOT A, you need to prove one or another, so you need to prove that A = X or that A != X.
Ok, the point is, these are 2 working, acceptable and valid mathematical systems, but they cannot be swapped, because CM != IM.
So, NO, two math systems CANNOT be translated back and forth. This is but the tip of the iceberg.