>At 20:50 11/07/2002, Ian wrote: >>When I first read The Code Book (Simon Singh), I drooled endlessly at >>the idea of Unbreakable Encryption, until I became a little more >>cynical. I questioned Dr Singh on this when he came and gave a lecture >>in Cheltenham UK recently, and his best answer was that QKD is so secure >>because "its a different kind of system. Its not like conventional >>encryption." [synopsis - not direct quotation]. I'm not thorougly >>convinced. >> >>Can anyone (politely) prove this mere outsider wrong? > >I am also not a physicist. So I share your skepticism about relying for >security on physic theories which I don't understand, and furthermore >which may evolve and refine over time. > >However, as many people are excited about Quantum crypto, I really would >like to put my skepticism aside and understand what is its cryptographic >significance, say if we accept the physics as valid (for ever or at least >`long enough`). In particular I'm considering whether I should and can >cover this area in my book. I must admit I haven't yet studied this area >carefully, so my questions may be naive, if so please excuse me (and your >answer will be doubly appreciated). Some questions: > >1. Quantum key encryption seems to require huge amounts of truly random >bits at both sender and receiver. This seems impractical as (almost) truly >random bits are hard to produce (especially at high speeds). Is there a fix? >2. After the transmission, the receiver is supposed to tell the sender how >it set its polarization; how is this authenticated? If it isn't we are >obviously susceptible to man in the middle attack. >3. It seems the quantum link must connect directly from sender to >receiver. How can this help provide end to end security on the Internet? >Or are we back to private networks? >4. As to quantum computation signalling the end of `crypto as we know >it`... Is it fair to say this may end only the mechanisms built on >discrete log and/or factoring, but not shared key algorithms like AES and >some of the other public key algorithms? > >Best, Amir Herzberg
-------------------------------------------------------------------------------------------------------------------------------- Amir Herzberg See http://amir.herzberg.name/book.html for draft chapters from `Introduction to Cryptography, Secure Communication and Commerce`, and link to lectures. Comments appreciated. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
