by having a plaintext and cyphertext, a quantum computer can make it very trivial to find the key using certain iterative attacks on the algorithm.
I mean, isn't the quantum computer "instantly" backtracking up until the substitution step of each round, as the operations would be reversible up until that point? I would think the complexity to crack is only dependant on the number of rounds.
There is no possibility to use a quantum computer to make simultaneous dictionary attack (guessing the key by trying all possible keys at the same time), because, contrary to what most people think, you can do only one usable computation at the same time on a quantum computer. The difference between classical and quantum computer is that you can 'tune' the quantum computer into doing this one computation which is important -- like the one needed to break the key. If you can do that, you've cracked the cipher. But it requires an algorithm specific to the cipher in question. A good defense before such attack would be to change the cipher in such a way as to make the corresponding quantum algorithm useless, and make attacker think really hard before coming up with another one. A bit more challenging than just increasing the key length.
IANAQCE (I Am Not A Quantum Computing Expert), but that's what I gathered from listening to seminars delivered by people from the field.
Re:Nope, wrong, invalid.. nothing to see here.
on
The End of Encryption?
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· Score: 2, Insightful
I've always wondered what would happen if some 15-year-old math wiz who is playing around in Mathematica comes up with a novel approach to factoring
If anybody does something about factoring, he will do it with pencil and paper (or blackboard and chalk), not with Mathematica. Mathematica is only as good as the mathematicians are, it's not a magic box sent from heaven.
quantum computing poses another threat to "classic" public key cryptography.
Not in predictable future. Quantum computing is still on the level of manufacturing single cubits and making them work together. It's worse than Babbage machine, when it comes to practical use.
There is censorship in any form, internet or print in any country. It just happens to be that China is not as sophisticated in hiding their techniques as other countries that have had better practice at it.
Or perhaps they want people to know so when you are successful at using one of the banned keywords you are that much easier to prosecute.
As if Chinese government needed any pretext to put people it wants in prison...
I strongly suggest you, read up what "censorship" means and stop saying "everywhere it's the same". When my father in Poland graduated from high school (with a technical profile, for electricians), he needed to xerox (in 70's) some articles for his diploma thesis. He needed to get a censorship permit for that. In the 60', people buying larger amounts of typewriter paper were under suspicion. This is censorship crippling people's lives at its best. When I visited Byelaruss with my grandmother a few years ago, the customs officer's greatest interest was in our books we took for travel. Sometimes it is good to have a frame of reference before issuing opinions.
I can think of a few books that have effectively (and possibly for good reason) disappeared from library shelves and retreated to professors' bookshelves in recent times. One title from 30 years ago comes to mind. (No, I don't own a copy.)
I thought that "Mein Kampf" was published earlier.
Many tinfoil hatters said the same thing when Disney refused to distribute F9/11 by Moore, yet that movie had the best opening for a documentry.
Disney is a private company, not a civil liberties group. It has the freedom (as in freedom) to decide which movies it likes to distribute, and which not. It's for their shareholders to decide whether it was a good move or not.
Tinfoil hatters also yelled censorship when the U.S. news outlets declined to air the beheadings enough though a simple web search turns up tons of websites with the footage.
Freedom of speech also has its limits, like the respect for the dead and their families.
I've been told there's legislation in the works to prohibit the sale of firearms used in a war. Meaning M16s, sure. But that also includes WWI-era Springfield rifles and 18th and 19th century muzzleloaders.
It is easy to render a rifle unusable. If someone collects this stuff for reasons of historical interest, he doesn't need to shoot from it (and most propably won't, because his precious item might blow up, taking a large part of his arm with it). Just make it illegal to sell usable rifles used in war.
They could be used in magnetic tyres (the kind that has sensors deducing the way a tyre deflects during breaking by the change in the magnetic field generated by magnetic powder interspersed in the tyre's rubber). Instead of mixing magnetic material with rubber, one could mix these polymers with rubber. Maybe it would work better, I don't know.
You need ferromagnetic stuff for hard drives, don't you? These polymers are not ferromagnets, I'm afraid. At least the original article doesn't say they are.
I know more than one legal secretary who thinks WP 5.1 was the best word processor ever
For those who learned it in the past, may well be. I know that it acquired a bit of a cult status. WP 5.1 for DOS will run on almost any hardware (I ran it on 286 PC). The problem is, it's much harder to use than Word, even Word 2.0. I tried to teach my grandomother (she's a professor in Polish literature) to write in WP 5.1 for DOS, and failed. The next try was with Word 2.0 and it succeeded, so we stuck with it (not that anything better would run on her computer).
This is why Word is still the dominate WP. It's got at least a little bit of everything you need; if you're willing to live with some odd quirks, you can even use it to replace almost all of the rest of Office.
I found the original article overhyped. It's just a "one sample effect". They need to present a method of producing (even highly inefficiently) ferromagnetic polymers, which works at least most of the time. Right now, they are probably guessing "but how did we do it???".
People were delivering similar reports on "discovery of room temperature superconductivity" in the past. The trouble is, they could not repeat their achievements. They were also from Croatia, which didn't give them that much publicity.
Well a fundamental new design has to be implemented, and I guess that's where quantum computing steps in...
Quantum computing is a new way of making calculations, not just a new way of making a CPU. The next step would be spintronics, where the bits are encoded in the spin (not voltage), but still the computer would work similarly to current ones.
Slashdot Mirror
by having a plaintext and cyphertext, a quantum computer can make it very trivial to find the key using certain iterative attacks on the algorithm. I mean, isn't the quantum computer "instantly" backtracking up until the substitution step of each round, as the operations would be reversible up until that point? I would think the complexity to crack is only dependant on the number of rounds.
There is no possibility to use a quantum computer to make simultaneous dictionary attack (guessing the key by trying all possible keys at the same time), because, contrary to what most people think, you can do only one usable computation at the same time on a quantum computer. The difference between classical and quantum computer is that you can 'tune' the quantum computer into doing this one computation which is important -- like the one needed to break the key. If you can do that, you've cracked the cipher. But it requires an algorithm specific to the cipher in question. A good defense before such attack would be to change the cipher in such a way as to make the corresponding quantum algorithm useless, and make attacker think really hard before coming up with another one. A bit more challenging than just increasing the key length.
IANAQCE (I Am Not A Quantum Computing Expert), but that's what I gathered from listening to seminars delivered by people from the field.
I've always wondered what would happen if some 15-year-old math wiz who is playing around in Mathematica comes up with a novel approach to factoring
If anybody does something about factoring, he will do it with pencil and paper (or blackboard and chalk), not with Mathematica. Mathematica is only as good as the mathematicians are, it's not a magic box sent from heaven.
quantum computing poses another threat to "classic" public key cryptography.
Not in predictable future. Quantum computing is still on the level of manufacturing single cubits and making them work together. It's worse than Babbage machine, when it comes to practical use.
They also spoof DNS responses, too: http://www.dit-inc.us/hj-09-02.html.
There is censorship in any form, internet or print in any country. It just happens to be that China is not as sophisticated in hiding their techniques as other countries that have had better practice at it. Or perhaps they want people to know so when you are successful at using one of the banned keywords you are that much easier to prosecute.
As if Chinese government needed any pretext to put people it wants in prison...
I strongly suggest you, read up what "censorship" means and stop saying "everywhere it's the same". When my father in Poland graduated from high school (with a technical profile, for electricians), he needed to xerox (in 70's) some articles for his diploma thesis. He needed to get a censorship permit for that. In the 60', people buying larger amounts of typewriter paper were under suspicion. This is censorship crippling people's lives at its best. When I visited Byelaruss with my grandmother a few years ago, the customs officer's greatest interest was in our books we took for travel. Sometimes it is good to have a frame of reference before issuing opinions.
and I can read /. sans all the conspiracy theories and communist America predictions....
s/communist/fascist
I can think of a few books that have effectively (and possibly for good reason) disappeared from library shelves and retreated to professors' bookshelves in recent times. One title from 30 years ago comes to mind. (No, I don't own a copy.)
I thought that "Mein Kampf" was published earlier.
Many tinfoil hatters said the same thing when Disney refused to distribute F9/11 by Moore, yet that movie had the best opening for a documentry.
Disney is a private company, not a civil liberties group. It has the freedom (as in freedom) to decide which movies it likes to distribute, and which not. It's for their shareholders to decide whether it was a good move or not.
Tinfoil hatters also yelled censorship when the U.S. news outlets declined to air the beheadings enough though a simple web search turns up tons of websites with the footage.
Freedom of speech also has its limits, like the respect for the dead and their families.
I've been told there's legislation in the works to prohibit the sale of firearms used in a war. Meaning M16s, sure. But that also includes WWI-era Springfield rifles and 18th and 19th century muzzleloaders.
It is easy to render a rifle unusable. If someone collects this stuff for reasons of historical interest, he doesn't need to shoot from it (and most propably won't, because his precious item might blow up, taking a large part of his arm with it). Just make it illegal to sell usable rifles used in war.
They could be used in magnetic tyres (the kind that has sensors deducing the way a tyre deflects during breaking by the change in the magnetic field generated by magnetic powder interspersed in the tyre's rubber). Instead of mixing magnetic material with rubber, one could mix these polymers with rubber. Maybe it would work better, I don't know.
You need ferromagnetic stuff for hard drives, don't you? These polymers are not ferromagnets, I'm afraid. At least the original article doesn't say they are.
Plus, it looks cool.
What about a virtual card? You get a VISA-like number, but they can charge it only as much as you put on the card.
This said, I do most of my online shopping in Poland by simple bank transfers (via online bank).
Or do linear regression? Will it be still Word, or Visual Basic?
I know more than one legal secretary who thinks WP 5.1 was the best word processor ever
For those who learned it in the past, may well be. I know that it acquired a bit of a cult status. WP 5.1 for DOS will run on almost any hardware (I ran it on 286 PC). The problem is, it's much harder to use than Word, even Word 2.0. I tried to teach my grandomother (she's a professor in Polish literature) to write in WP 5.1 for DOS, and failed. The next try was with Word 2.0 and it succeeded, so we stuck with it (not that anything better would run on her computer).
This is why Word is still the dominate WP. It's got at least a little bit of everything you need; if you're willing to live with some odd quirks, you can even use it to replace almost all of the rest of Office.
You mean, I can calculate my mortgage with Word?
Well, Croatia is a Balkan country, so...
"Room temperature" in physics means around 20 degrees Celsius, or sometimes simply 300 K.
Still amazing to see a design as old as I am still in use.
Look in the mirror, you'll see another one.
I found the original article overhyped. It's just a "one sample effect". They need to present a method of producing (even highly inefficiently) ferromagnetic polymers, which works at least most of the time. Right now, they are probably guessing "but how did we do it???".
People were delivering similar reports on "discovery of room temperature superconductivity" in the past. The trouble is, they could not repeat their achievements. They were also from Croatia, which didn't give them that much publicity.
However, any VISA will pass the security. After some sharpening, you can cut somebody's throat with it.
What's even more bizzare is that the article doesn't link to the ThinkGeek page for this. Instead, they link to a competitor, thetechzone.com.
Congratulations slashdot! you've just shot your sister-company in the foot!
No, they've just DDoS'ed^H^H^H^Hslashdotted the competition.
Did the author of the book write anything on FORTRAN?
56,34% of all statistics is taken out of thin air.
Well a fundamental new design has to be implemented, and I guess that's where quantum computing steps in...
Quantum computing is a new way of making calculations, not just a new way of making a CPU. The next step would be spintronics, where the bits are encoded in the spin (not voltage), but still the computer would work similarly to current ones.
A soldier at D-Day pinned down on the beach that manages to take out a German pillbox
Exactly when did Iraqi army offered resistance comparable to German army's?