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‘Unbreakable’ quantum cryptography hacked without detection using lasers

13 points by nickb 18y ago

hugh 18y ago
Almost certainly either: a) Complete BS, or b) Not what it sounds like, but it's not possible to figure out which from this article, which provides no information. If anyone has a link to a better explanation, I'd love to read it. The closest thing to a clue is this vague statement: The intruder simply hooks into what the receiver is receiving (which is actually very complex). which sounds to me like the intruder is, in essence, looking over the receiver's shoulder.
- hugh 18y ago
  Aha, I found the paper: http://arxiv.org/abs/0809.3408 http://arxiv.org/abs/0809.3408 It's all about exploiting vulnerabilities in the type of single-photon detectors that are used in real systems. Looks like pretty clever stuff.
tlrobinson 18y ago
Sooo how exactly does this work? The article seems to be a bunch of handwaving.
- nickb 18y ago
  See: http://news.ycombinator.com/item?id=323856 http://news.ycombinator.com/item?id=323856
tptacek 18y ago
I stopped reading at "quantum cryptography is used to secure Swiss bank transactions". The highest conceivable levels of finance are protected using nothing more exotic than SSL/TLS. I'm sure there's an awesome paper buried somewhere in this story, but I'm equally sure this reporter has no idea what it means.
- nihilocrat 18y ago
  Scroll up a bit, by the looks of the comments it seems like it's another case of "clueless journalist makes a hokey-sounding story about a real technology". This is why I don't generally ever read online articles about technology written by 'normal' news outlets.
RK 18y ago
Maybe michael_nielsen can give us some insight on this story.
- michael_nielsen 18y ago
  Not much to add beyond what's already been said. The linked article isn't very good, but the paper itself may be correct. I haven’t checked the paper, but the possibility of this kind of break is quite plausible. The reason is that when quantum cryptography researchers say quantum cryptography is "unbreakable", there’s many unspoken caveats. All they mean is that the theoretical scheme itself is unbreakable. Of course, (a) the real-world implementation may differ in subtle ways from the theoretical scheme; and (b) side-channel attacks cannot be ruled out. Both these possibilities can potentially be exploited to crack quantum cryptography. I’ve written about this at some length at: http://michaelnielsen.org/blog/?p=122 http://michaelnielsen.org/blog/?p=122 If you feel a bit cheated by this state of affairs, given the hype that often surrounds quantum cryptography, I don’t blame you.

13 points by nickb 18y ago

hugh 18y ago

Almost certainly either: a) Complete BS, or b) Not what it sounds like, but it's not possible to figure out which from this article, which provides no information. If anyone has a link to a better explanation, I'd love to read it. The closest thing to a clue is this vague statement: The intruder simply hooks into what the receiver is receiving (which is actually very complex). which sounds to me like the intruder is, in essence, looking over the receiver's shoulder.

hugh 18y ago
Aha, I found the paper: http://arxiv.org/abs/0809.3408 http://arxiv.org/abs/0809.3408 It's all about exploiting vulnerabilities in the type of single-photon detectors that are used in real systems. Looks like pretty clever stuff.

tlrobinson 18y ago

Sooo how exactly does this work? The article seems to be a bunch of handwaving.

nickb 18y ago
See: http://news.ycombinator.com/item?id=323856 http://news.ycombinator.com/item?id=323856

tptacek 18y ago

I stopped reading at "quantum cryptography is used to secure Swiss bank transactions". The highest conceivable levels of finance are protected using nothing more exotic than SSL/TLS. I'm sure there's an awesome paper buried somewhere in this story, but I'm equally sure this reporter has no idea what it means.

nihilocrat 18y ago
Scroll up a bit, by the looks of the comments it seems like it's another case of "clueless journalist makes a hokey-sounding story about a real technology". This is why I don't generally ever read online articles about technology written by 'normal' news outlets.

RK 18y ago

Maybe michael_nielsen can give us some insight on this story.

michael_nielsen 18y ago
Not much to add beyond what's already been said. The linked article isn't very good, but the paper itself may be correct. I haven’t checked the paper, but the possibility of this kind of break is quite plausible. The reason is that when quantum cryptography researchers say quantum cryptography is "unbreakable", there’s many unspoken caveats. All they mean is that the theoretical scheme itself is unbreakable. Of course, (a) the real-world implementation may differ in subtle ways from the theoretical scheme; and (b) side-channel attacks cannot be ruled out. Both these possibilities can potentially be exploited to crack quantum cryptography. I’ve written about this at some length at: http://michaelnielsen.org/blog/?p=122 http://michaelnielsen.org/blog/?p=122 If you feel a bit cheated by this state of affairs, given the hype that often surrounds quantum cryptography, I don’t blame you.