Random photons in optical systems are easy to get at hight speed, a flame.
BEC's also have the capability to make some significant breaks in the security of optical encryption. For example, one can trap a photon in a BEC, measure it's parameters at one of the BEC-component atoms, then re-emit the photon without changing its state (the trick is we are measuring a part of the photon not the entire photon, and the photon is standing still - frozen in time). > ---------- Forwarded message ---------- > Date: Sun, 14 Jul 2002 15:24:48 +0200 > From: Amir Herzberg <[EMAIL PROTECTED]> > To: [EMAIL PROTECTED] > Subject: Fwd: Re: Quantum Computing Puts Encrypted Messages at Risk > > > >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] > -- ____________________________________________________________________ When I die, I would like to be born again as me. Hugh Hefner [EMAIL PROTECTED] www.ssz.com [EMAIL PROTECTED] www.open-forge.org --------------------------------------------------------------------