Quantum Cryptography Ready For Wide Adoption?
An anonymous reader points us to an interview with the founder of quantum cryptography pioneer MagiQ Technologies. From the article: "Q: When do you think we'll see service providers offer quantum cryptography services to their end-customers? A: This will happen within one year and we'll see fairly wide adoption within the next three years. We are working with big carriers such as Verizon and AT&T as well as some companies that own fiber networks. The goal is to embed quantum cryptography into the technology infrastructure so it becomes totally transparent to the end-user..." The cost of a pair of MagiQ boxes to implement point-to-point encryption on a 120-km link is $100,000 plus service.
The only way to see if this works is to break the fibre connection and see if it notices.
Oh lookie, the amazing thing is - a normal fucking fibre circuit will notice as well.
There is no quantum tech yet.
This is just going to increase our month subscriptions without giving any benefits, we will still use encryption on every required connection and will still have open holes alopng the way (last mile), so who exactly does it benefit?
I suggest any carrier should pay them with money stored in a quantum envelope. You are certain it contained $100,000 before you sealed it up, if its not there now it must have been intefered with.
liqbase
As a component of a broader security system, cryptography is valuable and solves many problems.
History shows that the weak links in systems employing cryptography is usually some other part of the system. DVD's are an obvious example.
Outside of gov't agencies and the mega-corps that service them, I don't see this taking off like the ipod. The PHB's in the banking world certainly won't understand why this is better than the systems they have now.
http://www.maxineudall.com/2010/02/should-economists-be-sued-for-malpractice.html
But I'd rather the lines were upgraded to support faster speeds first. That should be a higher priority than embedding encryption into the network. There is little pressing need for better encyption, but more data bandwidth would help a lot of things.
'Sensible' is a curse word.
by definition Quantum cryptography can not be run on real networks were you have to do things like routing.
In practice, quantum cryptography doesn't achieve anything that regular crypto systems like SSL or ipsec don't. Quantum cryptography is theoretically unbreakable, whereas SSL is believed but not mathematically proven to be unbreakable. In either case, it's easiest for an attacker to compromise one of the endpoints, so it's not a big difference. SSL is cheap, easy and widely deployed. So why would anyone spend $100,000+ per link on untested quantum cryptography hardware, when you could roll out ipsec much more cheaply?
Worse, they talk about "repeaters" to extend the range past 120km - which is scary, because it implies they are decrypting/recrypting at the repeater.
Can you say "Physical Security"? I knew you could.
Clear, Dark Skies
I had mod points, but what the hell, this is an important point....
You are correct in pointing out (as most responsible qcrypto people do), that qcrypto needs authentication.
However, your argument doesn't follow
So even if you use QC, you still need to rely on all the classical crypto to make it work. So it is just as good as classical crypto, without routing.
The reason is that:
1) The authentication only needs to be secure for a second or two. I just use it foil a man-in-the-middle-attack or authenticate part of the protocol. So, if I use public key authentication, and the public key is then cracked, no problem, I've already used it to authenticate. The cracked key is now useless to the attacker. So, my attacker may even have a quantum computer, but she would still need more than a few seconds to crack the classical crypto.
2) Authenticating a message uses a very small amount of key (logarithmic), so if I start off with a small key from magicQ, then I can expand it, thus generating an arbitrary large amount of secret key from a tiny "seed". Thus sometimes, qcrypto is called "key expansion".
So, if you want to protect your data against future attacks (who knows how good algorithms and computers will get), or when we start needing to worry about quantum computers, then we will have to switch to quantum crypto-- it is just a matter of time.
As an aside, no responsible qcrypto person would suggest monitoring the fibre as a solution.
Deconstruct the State
You post sounds like it is based on a misconception that QC is allowing Alice to transmit to Bob a secret. This is not what is going on at all; rather, a shared secret is being generated that Alice does not even know until the end of the process. In classical crypto, a man could sit in the middle and figure out the secret that is shared between Alice and Bob. In properly implemented quantum crypto, however, this is not possible. The best he could do -- using the very man in the middle attack that you described -- is to have one secret that is shared with Alice, and a separate secret that is shared with Bob, when Alice and Bob both think that they have a secret that is shared with each other. It is unlikely that Alice and Bob would take very long to notice that they are using different keys, given that this would produce garbage in every single message that they exchanged.
It's true that he could then hijack ALL communication channels between Alice and Bob, decrypt messages using one key and then re-encrypt them using the other, but... it would probably be easier just to bribe the people doing the transmitting and receiving to tell him what the messages were. I don't think that most people who are serious about security are claiming that QC is a miricule cure, just that it makes one part of the system much, much more secure.
It might be the case that the benefit is not worth the cost, given that the weakest link tends to be the human element, but this is much different than it being "just as good as classical crypto", or a form of "snake oil".
Snarkiness is inversely proportional to wisdom because it emphasizes feeling right rather than being right.
Only benefit of QCrypto over classical crypto: It stops evesdropping. Problem: It doesn't stop some forms of man in the middle. All this stuff you've said is true, but I don't think it really contradicts the parent. QCrypto is hyped as being unbeatable, which it clearly isn't. The massive effort you think it would take to hijack ALL communications channels between Alice and Bob, is really not that big a deal- you wouldn't man in the middle the QCrypto link unless you knew the other channel the message is going over and could MitM that too. I'm still massively unimpressed with QCrypto. On top of that, there are other ways that may be just as effective at stopping evesdropping, see "hold the photons" by Bruce Scheier in wired.
It's true that he could then hijack ALL communication channels between Alice and Bob, decrypt messages using one key and then re-encrypt them using the othe
I thought this is EXACTLY what a man-in-the-middle attack was. If you have another communication channel that doesn't have an attacker between Alice and Bob, Alice and Bob are always going to figure out that they aren't sharing the same key.
but... it would probably be easier just to bribe the people doing the transmitting and receiving to tell him what the messages were
Well sure.. but it's also easier to do that than crack conventional cryptography. So given this, what advantage does quantum cryptography have?
AccountKiller