Serious Flaw Emerges In Quantum Cryptography
technologyreview.com
Serious Flaw Emerges In Quantum Cryptography
1–10 of 47 posts
Re: Serious Flaw Emerges In Quantum Cryptography
#2If I'm understanding this correctly, the "serious flaw" recently uncovered is that if the manufacturer of the crypto devices is malicious, the crypto devices can be made to be insecure. Despite the fact that this same "serious flaw" exists with classical cryptography devices, only worse (since the quantum attack doesn't reveal plaintext A until B is sent).
(Disclosure: haven't bothered to read the arXicle.)
Re: Serious Flaw Emerges In Quantum Cryptography
#3If I'm understanding this correctly, the "serious flaw" recently uncovered is that if the manufacturer of the crypto devices is malicious, the crypto devices can be made to be insecure. Despite the fact that this same "serious flaw" exists with classical cryptography devices, only worse (since the quantum attack doesn't reveal plaintext A until B is sent). (Disclosure: haven't bothered to read the arXicle.)
I read it and you're right. I'm puzzled as to why they would think this 'scuppers' all of quantum cryptography. They also mention imperfect hardware, but hardware always improves.
Re: Serious Flaw Emerges In Quantum Cryptography
#4If I'm understanding this correctly, the "serious flaw" recently uncovered is that if the manufacturer of the crypto devices is malicious, the crypto devices can be made to be insecure. Despite the fact that this same "serious flaw" exists with classical cryptography devices, only worse (since the quantum attack doesn't reveal plaintext A until B is sent). (Disclosure: haven't bothered to read the arXicle.)
I read it and you're right. I'm puzzled as to why they would think this 'scuppers' all of quantum cryptography. They also mention imperfect hardware, but hardware always improves.
This obviously doesn't have any impact on those who own and trust the sender and receiver and only need to be cautious about what happens in between them. However, part of the desire for device independent security is that you can use public infrastructure without trusting it and still be certain that your communication is secure. i.e. If quantum networks replace/augment classical networks, can you trust them without controlling them? This work suggests that dream may be more difficult to achieve that previously thought, although the jury is most assuredly still out.
Re: Serious Flaw Emerges In Quantum Cryptography
#5If I'm understanding this correctly, the "serious flaw" recently uncovered is that if the manufacturer of the crypto devices is malicious, the crypto devices can be made to be insecure. Despite the fact that this same "serious flaw" exists with classical cryptography devices, only worse (since the quantum attack doesn't reveal plaintext A until B is sent). (Disclosure: haven't bothered to read the arXicle.)
Despite the fact that this same "serious flaw" exists with classical cryptography devices, only worse (since the quantum attack doesn't reveal plaintext A until B is sent).
How would you do this with classical cryptography?
Isn't the point about this particular flaw that it is pretty much undetectable (other than inspecting the hardware itself (which is outside the scope of the article that treats it as a black box)). If the same were to be implemented on classical cryptography it would be comparatively trivial to detect if someone tried to sneak in an old message interleaved with a new message (you know the plaintext + key and thus you know exactly what that will generate).
The compelling argument for quantum cryptography is that it is provably secure (well, that's the theory) and it is quite difficult to prove that the hardware has not been tampered with.
The thing you could do with classical cryptography is to in some way "leak" the key (such as what debian inadvertently did with openssl) but the whole point of quantum cryptography is to have a perfect key distribution to combat any known or unknown attacks.
I found the abstract, http://arxiv.org/abs/1201.4407 , shorter and more informative than the article.
Re: Serious Flaw Emerges In Quantum Cryptography
#6Okay, here I go on a tangent:
If I buy two 5-bay DROBOs, 10 2 TB HDs, and a hardware random number generator, I could make a multi-TB One Time Pad, and copy it onto the second DROBO.
I keep DROBO one, and physically carry DROBO two to my intended recipient.
What are the problems with this?
It's cheap. It's as secure as any communication could possibly be. It provides for a whole lot of communication, with relatively little physical effort.
Re: Serious Flaw Emerges In Quantum Cryptography
#7Okay, here I go on a tangent: If I buy two 5-bay DROBOs, 10 2 TB HDs, and a hardware random number generator, I could make a multi-TB One Time Pad, and copy it onto the second DROBO. I keep DROBO one, and physically carry DROBO two to my intended recipient. What are the problems with this? It's cheap. It's as secure as any communication could possibly be. It provides for a whole lot of communication, with relatively…
You can't prove that you can trust the carrier. And with trust I not only mean that the carrier has good intentions but also that the carrier is physically unable to do any mistakes.
Also you can't prove that someone doesn't sniff the traffic when you copy it to your second DROBO and you can't prove that none of the drives have been copied afterwards.
Not saying that your approach isn't "secure enough" (I'd guess that's what they do on submarines?), but compared to (the theory of) quantum cryptography it has many flaws.
Re: Serious Flaw Emerges In Quantum Cryptography
#8i don't understand how it is not susceptible to MITM attacks. how do you know you know the thing at the other end is really who you want to talk to without using some kind of preshared key? maybe an eavesdropper can't view the conversation between you and the other end but that doesn't matter if someone can easily pretend to be the other end.
Re: Serious Flaw Emerges In Quantum Cryptography
#9Okay, here I go on a tangent: If I buy two 5-bay DROBOs, 10 2 TB HDs, and a hardware random number generator, I could make a multi-TB One Time Pad, and copy it onto the second DROBO. I keep DROBO one, and physically carry DROBO two to my intended recipient. What are the problems with this? It's cheap. It's as secure as any communication could possibly be. It provides for a whole lot of communication, with relatively…
You can't prove that you can trust the carrier. And with trust I not only mean that the carrier has good intentions but also that the carrier is physically unable to do any mistakes. Also you can't prove that someone doesn't sniff the traffic when you copy it to your second DROBO and you can't prove that none of the drives have been copied afterwards. Not saying that your approach isn't "secure enough" (I'd guess tha…
Thanks for the reply!
> You can't prove that you can trust the carrier.
I said that I physically carry DROBO two to my intended recipient. I can trust myself.
> Also you can't prove that someone doesn't sniff the traffic when you copy it to your second DROBO and you can't prove that none of the drives have been copied afterwards.
There is no such thing as secure communication. Copying data from one DROBO to another DROBO is about as secure as I could possibly imagine.
Physical security is a failure point in any system. As much as I can trust my sending location, and my receiving location, I can trust this system.
> compared to (the theory of) quantum cryptography it has many flaws.
Compared to quantum cryptography:
I can't prove that I trust the person who set up the quantum cryptography system.
I can't prove that someone doesn't sniff my connection to my quantum key system. I can't prove that someone doesn't sniff the data coming out on the receiving end.
I think this all boils down to physical security - which is a problem in any secure communication system.
And I think my two DROBO, ten HD, one hardware random number generator, one round-trip plane ticket, system is about - mmm - 4 to 6 orders of magnitude cheaper.
Re: Serious Flaw Emerges In Quantum Cryptography
#10Okay, here I go on a tangent: If I buy two 5-bay DROBOs, 10 2 TB HDs, and a hardware random number generator, I could make a multi-TB One Time Pad, and copy it onto the second DROBO. I keep DROBO one, and physically carry DROBO two to my intended recipient. What are the problems with this? It's cheap. It's as secure as any communication could possibly be. It provides for a whole lot of communication, with relatively…
If either side is compromised it is difficult to reissue (e.g. if they are undercover in another country).
The beauty of public keys is that they can be revoked and the other side can use your new key without you having to transport/transmit a private key in peril.