This just showed up on _cryptography_ and illuminates the point various nyms were making here about QM, randomness, and ignorance. Reproduced without permission. Hannes said,

What we have here is a theory which is almost as old as the special theory of relativity and has not yet prooven wrong. This theory tells us that there is no way whatever, that a possible eavesdropper can listen to the key exchange.

I appreciate your statement and I am sure you have the experise in the area. However, to rely on a security/crypto mechanism, I must see a proof I understand, and I _never_ rely on `proof by intimidation`. In this case, I'll like a proof showing reduction from a specific theorem which is backed by many years of concentrated effort to break it. I am not cynical, really. I will really appreciate if you provide me/us with (reference) to (a) historical evidence of a precise theorem/conjecture which withstood many years of substantial scurtiny, and (b) precise proof, with sufficient details for someone (like me) whose physics is rusty (many years since my engineering school days...), showing the reduction from the specific claims to the long-lived theorem.

It also > tells us that if we use either a Quantum random number generator or an entangled photon QKD system, that we get absolutly random numbers.

Can you generate truly random numbers? Cool! Indeed, this is something which in a sense is to be expected, based on the uncertainty principle. Of course, for a complete QKD system this may be a small part; but this part could be useful for many crypto systems, if it is really secure - and practical (cost, size, etc.). Can you provide details on this? As an aside note, the uncertainty principle may be an example of physical theory which have withstood many years, but I doubt that it was really tested using crypto principles. I mean, couldn't it just turn out that all of the randomization in physics will some day turn out to be pseudo-random??? After all, detecting the difference could be fairly difficult, even if and when we learn the details of this supposed pseudo-random generator, assuming it is a non-trivial one (after all even the congruential generator was only fairly recently shown insecure!). Regards, Amir Herzberg See http://amir.herzberg.name/book.html for lectures and draft-chapters from book-in-progress, `Introduction to Cryptography, Secure Communication and Commerce`; feedback appreciated! --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com