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How To Build a Quantum Eavesdropper
KentuckyFC writes "Quantum encryption is perfectly secure, in theory. In practice, however, there are loopholes. Now Japanese scientists have designed a quantum eavesdropper that exploits one of these loopholes to listen in to quantum conversations. QC's security arises from the impossibility of making a perfect copy of a quantum object without destroying it — so the sender and receiver can always tell if they've been overheard. But it turns out that an eavesdropper can make imperfect copies and use them to extract information from a quantum message without alerting sender or receiver (abstract). The Japanese design does just this. That should worry banks and government agencies that have begun to use some of the commercial quantum encryption systems now available."
But Al, why haven't I leaped?
Ziggy says there's a 98.5% chance that your security is flawed.
The Internet is generally stupid
You don't need anything so fancy. The quanta are, like packets, not guaranteed to get tot he destination every time. All you have to do is sidetrack every random(N)'th photon to your receptor.
Having been involved in abstract quantum physics in my college grad student days, I can say that this is quite a tall order. The whole point of quantum cryptography is that the observation changes the system to the point that (a) eavesdropping disturbs the communications to the point of making it unusable and (b) due to (a) it is detectable oh what the hell am I talking about. First post. That's right, I just nailed a frosty.
I think this story is a better candidate for the "South Park" defense than the Chinese Gov't Hackers.
I've been droppin' no eaves sir.
How can one say that it is "theoretically impossible", when somebody has made a practical counterexample? It just means that the theory wasn't good enough - or more likely, that the wrong conclusions were made from the theory.
IANAP, but can someone please tell me how the theoretically impossible became theoretically possible? Did the theory change, or was the math wrong, or did His Great and Wonderful Noodliness screw with the results?
If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
The banking sector is probably one of the slowest in terms of uptake of new crypto technologies. A huge number are still using 3DES or RC4 for symmetric to protect customers transactions. If you don't believe me, check out Citibank's Online Banking with "highly modern" RC4. I've seen 40-bit encryption on current express-pay keytags at a certain coffee chain which is almost trivial to crack with little cost by today's computers. In too many cases, it's the same old HSMs accelerating crypto transactions in servers as were in the last decade.
Granted, 3DES is actually not truly that bad in terms of its 112-bit effective security compared to AES-128 (though it's not the weak point when you use 80-bit effective RSA1024). However, just because ANSI X9 has started including modern technologies like ECC and AES or other technologies like quantum crypto are promising, you can bet that the banking industry will be one of the last groups to take up more modern crypto technology. Heck, even the NSA is mandating Suite B with ECC and AES by 2010 for government security! It's one of the few government agencies to actually act faster than the private sector.
Finally, I wonder if the original poster could show the relevant ANSI X9 aka banking security standard which calls out quantum crypto. I don't think I've seen one, and the banking industry typically lives and dies by X9.
By listening in with the Quantum eavesdropper, you've changed what they were actually saying!
http://clightnirish.wordpress.com/
If the 'eavesdropper' can only make 'imperfect' copies then it seems to me using multiple levels of security would defeat the eavesdropper. For example private key encrypted data being tunneled over the quantum channel. Using this technique they would get a copy of imperfect encrypted data - which would be impossible to decrypt even if you had the private key .
20 comments on a quantum mechanics article, and still no Schroedinger's Cat superposition jokes? What's Slashdot coming to these days?
How imperfect is the snooped data?
Just because you COULD get data out doesn't mean it is actually usefull to do so.
Okay, so you receive some imperfect data... isn't it still encrypted??
I know this isn't quite the same, but I can pull loads of data from surrounding wireless networks.. of course, it's still encrypted with WPA, so it's not of much use.
So what's the real threat?
I thought quantum encryption was just getting past the theory stage, now some boffins have already 'cracked' it. I'm so like, you know?, wow!, you know?
http://www.research.ibm.com/quantuminfo/teleportation/
It's a lucky thing the summary was good, because the only thing I could learn from the linked abstract is that "Francesco" is a Japanese name.
there are countries which do have decent banks.
like switzerland.
even government agencies have started testing quantum cryptography, to help secure the transmission of vote results.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
This is wrong. The eavesdropper gets imperfect copies and so does the receiver. If the quality of the receiver's copies are as bad as the eavesdropper's, any working quantum crypto setup will abort and not try to make a secret key out of it.
That should worry banks and government agencies that have begun to use some of the commercial quantum encryption systems now available.Nobody needs to worry about these kinds of attacks, as the software in all commercial quantum crypto systems automatically checks and takes care of these kinds of attacks. What the paper shows is how to implement in practice a class of attacks that has been known for years how to do in theory.
There are other attacks on quantum crypto systems that actually attack loopholes in the implementation, and some of these have previously been discussed on slashdot here
Why not use a more conventional, strong encryption method and then use quantum encryption on top of that? Getting an imperfect copy of a deeply encrypted message ought to be enough to drive anyone to drink including large numbers of enemy spies working in concert.
This is because old crypto is often a lot more secure than people would have you think. Many attacks even against very old algorithms remain impractical against a securely implemented scheme.
Even RC4 and DES can be secure when used correctly in situations where there isn't time to brute-force anything, and at least the insecurities and algorithms themselves are well understood, which isn't necessarily true for more modern algorithms. (I think this article is a good example of the latest buzz in crypto still being given a healthy poking and prodding prior to production use.)
The problems with RC4 and DES occur when someone who doesn't know anything about them decides to use RC4 with a password as the initializer to encrypt a document for long-term storage for their proprietary data format.
Amateur use of old crypto is worse than old crypto itself; lots of stuff encrypted using WW2 ciphers is still unrecoverable.
// MD_Update(&m,buf,j);
-FL
Like, I don't know ANYONE with a quantum computer, and these nerds are making and breaking quantum encryption already? What use is it if no one has the quantum machines to download movies anyway?! Where can I go to get myself an AMD Quantum Processor for under $300, huh?
Seriously though, one day you hear "Quantum Cryptography is UNBREAKABLE!", the next day you hear "Quantum Cryptography BROKEN!", it's just a circus. Can we solve the world hunger crisis first, anyone?! Sheesh.
buried as redundant.
I rarely trust any company that can't spell their own technology:
"id Quantique is the leader in the development of advanced encryption solutions based on classical and quantum cryptograhy."
cryptograhy?
Oooh, maybe they're trying to hide themselves through dodgy spelling! Cunning!
--- Band: Joey Ultra