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Commercial Quantum Cryptography System Hacked
KentuckyFC writes "Any proof that quantum cryptography is perfect relies on idealized assumptions that don't always hold true in the real world. One such assumption is related to the types of errors that creep into quantum messages. Alice and Bob always keep a careful eye on the level of errors in their messages because they know that Eve will introduce errors if she intercepts and reads any of the quantum bits in a message. So a high error rate is a sign that the message is being overheard. But it is impossible to get rid of errors entirely, so Alice and Bob have to tolerate a small level of error. This level is well known. Various proofs show that if the quantum bit error rate is less than 20 percent, then the message is secure. However, these proofs assume that the errors are the result of noise from the environment. Now, physicists have come up with an attack based on the realization that Alice also introduces errors when she prepares the required quantum states to send to Bob. This extra noise allows Eve to intercept some of the quantum bits, read them and then send them on, in a way that raises the error rate to only 19.7 percent. In this kind of 'intercept and resend attack,' the error rate stays below the 20 percent threshold and Alice and Bob are none the wiser, happily exchanging keys while Eve listens in unchallenged. The physicists say they have successfully used their hack on a commercial quantum cryptography system from the Geneva-based startup ID Quantique."
...to e-mail Alice and Bob, rather than advertise that their love-letters are being snooped on?
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
...stopping reading the blurb on slashdot last week about the new position based system being secure because the people who previously said it wasn't secure changed their mind and said it was provably secure and then proceeded to use the words "cannot easily" to justify it being secure. Now, this week I see a commercial system that has been cracked because some how thresholds of likely hood were once again used. Anyone else see a trend?
If this article is correct, all an eavesdropper has to know is the proper error threshold to stay under to remain undetected.
Doesn't seem so secure to me.
They could develop more sophisticated measurement techniques, similar to those utilized in modern data/telecom, as error thresholds become lower.
They could call it the Quantum Bit Error Rate Test, or Q-BERT for short.
The core idea of using quantum communication security (or, in general, quantum communication) is that you'll be able to tell when the message has been altered.
All a man in the middle attack has to do is read the message, recreate it, and send out a spoofed message instead of the original message.
Reading the message is trivial.
Recreating the message, while introducing tolerable levels of noise is trivial once you have the key. Alice does it all the time.
Blocking the original message is not trivial, but it is also not hard. It just requires physical access to the network. Be it jamming a wireless signal, splicing your attack node between two routers, whatever.
Sending out the spoofed message is trivial. The internet is slow and laggy. You can easily read, alter, and resend the message without the delay being noticed.
The only thing stopping a man in the middle attack is the need to have the key to resign an altered message as to make it appear that it came from Alice. This is a key-sharing problem. All digital security problems boil down to a key-sharing problem.
The only thing the quantum nature of communication adds is the ability to detect when people might be listening. This only gets around eavesdropping, not an actual MITM attack.
Indeed, the quantum nature of the "security", as this paper shows, actually opens the door to attacks, as the communication medium is not perfect and there is now a threshold for tolerable noise. Attacks can play around in that threshold all day long.
Really, is a little fidelity in this relationship too much to ask for? I've caught Bob kissing that skank Alice so many fucking times and he always says he's sorry and he'll stop seeing her, but still I can tell they're exchanging information through hidden channels.
But what I really hate is when people act like I'm so unreasonable by trying to find out what is going on and who my allegedly significant other is seeing behind my back. What the fuck.
-
Cryptographically Signed,
Eve.
(Inspired by xkcd, of course.)
Various proofs show that if the quantum bit error rate is less than 20 percent, then the message is secure. However, these proofs assume that the errors are the result of noise from the environment.
Then they do not "prove" anything.
When you start from a false premise, you produce "garbage", not "proofs" (Actually, you can produce some really useful counterfactuals that way, but you wouldn't present it in the context of a proof of the original concept). Particularly when talking about security, what moron would assume any sources of error come from the environment rather than the attacker???
Eve is a fucking spy, arrest her.
I'm not too sure about Alice and Bob either, seems they're always around when these things happen.
The ability to control external noise in real-world operating environments, at least to the degree necessary to mitigate this issue, would seem to represent a rather nasty challenge. This may be a severely constraining factor on the potential for practical usefulness of quantum cryptography, at least for the time being.
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
A 20% error rate isn't good enough to launch a missile, but it's better than a weatherman's accuracy. This tells us that Alice, Bob and Eve don't work for NORAD or the National Weather Service. That narrows down the field considerably. It won't be long before their identities are discovered, posted on TMZ and they won't need these silly quantum encrypted messages anymore.
can be broken by a man
depending upon your current situation in life, this is either a wonderfully hopeful or horribly depressing realization
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
One the main contributors to the error rate is the photon detection efficiency, where 80% or better is considered "good". In a major breakthrough last month, NIST (yes, the National Institute of Standards and Technology, not some startup company's marketing hype) has achieved a record single-photon detection rates of 99% - and possibly better, since there currently exists no metrology to test that level of efficiency. So in terms of that source of error, things are looking up.
Moreover, in our attack, Eve only sends two states to Bob. Alice and Bob can detect this attack by estimating the statistics of the four BB84 states. Note that, once a security loophole has been found, it is often easy to develop countermeasures. However, the unanticipated attacks are the most fatal ones.
www.RacquetUp.org - Helping Detroit Youth
The dark count is essentially zero. That's what makes this breakthrough so impressive.
FTA I linked:
"When these detectors indicate they've spotted a photon, they're trustworthy. They don't give false positives," says Nam, a physicist with NIST's Optoelectronics division. "Other types of detectors have really high gain so they can measure a single photon, but their noise levels are such that occasionally a noise glitch is mistakenly identified as a photon. This causes an error in the measurement. Reducing these errors is really important for those who are doing calculations or communications."
Thing is nowadays TB drives are quite cheap. Generate a huge OTP, spread it over three drives at A, spread it over another three drives and send all three to B via three different couriers/paths. Add ECC if you want.
If they all made it safely without interception. You've got your secure channel. 1TB/128kbps = 2 years. 1TB/256kbps = 1 year.
You could send more than one set of drives. When they all arrive, you tell the "B" let's start with drive set #5.
The ability to control external noise in real-world operating environments, at least to the degree necessary to mitigate this issue, would seem to represent a rather nasty challenge. This may be a severely constraining factor on the potential for practical usefulness of quantum cryptography, at least for the time being.
Can someone explain to me why anybody is even bothering with this technology?
Are existing cryptographic algorithms so untrustworthy that it's better to use an untested technology that a) makes the already very expensive line equipment significantly more expensive, b) may prevent the use of certain kinds of repeaters or active splices, c) is so insanely complex that nobody except a select few physicists understand the details.
Also, unlike current cryptographic techniques, quantum cryptography is strictly one hop instead of end-to-end, which is a big issue in many cases, like when one ISP tunnels their data over another ISP's link.
More importantly, it doesn't actually encrypt any of the data in the traditional sense. The data goes across the wire unencrypted, the quantum system just detects a man-in-the-middle attack. If someone comes up with a technique for reading the data without interference (like the article says), then you're screwed. With a traditional crypto solution, it might be sufficient to just increase the key size parameter in a config file somewhere!
I don't see how this can compete with standard crypto. If someone is that paranoid, it should be more than enough to just nest a couple of different algorithms together, and use the maximum keysizes for all of them. There's just no way anybody is breaking that at 2Tbps line rates any time soon, no matter what conspiracy theories you subscribe to about the NSA's capabilities!
Think about it this way: with traditional crypto, it's at least possible, in principle, for an end-user to use an open source software stack using an open, publicly tested algorithm, and completely verify the implementation. With quantum crypto, you get a black box with some physics in it that no IT administrator will understand and be able to test. It'll send data unencrypted across a wire that you now hope is hack proof. For all anybody knows, it'll be sending data as-is with no protection, and nobody will be able to even tell. If you were the NSA and wanted access to fibre optic links, wouldn't this be the best thing ever?
I say Bob should dump Alice and go with Eve. Bad girls are hot.
Though dumped good girls can be trouble as well, so the original problem remains.
Sadly, as long as Eve (or Alice) are sufficiently determined to intercept Bob's communications, he's got problems. The only answer may be to become a celibate monk in a monastery committedly observing a vow of silence.
Loose lips lose spit.