21 May 1999. Thanks to MS.

    Date: Fri, 21 May 1999 10:36:39 -0600
    From: Mike Stay <staym@accessdata.com>
    To: coderpunks@toad.com
    Cc: cryptography@c2.net
    Subject: quantum codebreaker

    There is a paper just published today on the Los Alamos Nat'l Labs
    preprint site:

       http://xxx.lanl.gov/abs/quant-ph/9905064

    on how to simulate arbitrary nonlinear quantum dynamics.  They give
    examples of existing systems where the effect has already been seen
    and then give a general description of using feedback to make a quantum
    system behave nonlinearly. They show that in such systems, distances
    between quantum states are NOT preserved.

    It was previously published hat if QM was nonlinear at all, one could
    do a quantum search in log N time instead of sqrt N time.

       http://xxx.lanl.gov/abs/quant-ph/9801041

       http://xxx.lanl.gov/abs/quant-ph/9804025

    If today's paper is correct, then it's just a matter of sufficient
    technology to break ANY code with a known-plaintext attack.
    --
    Mike Stay
    Cryptographer / Programmer
    AccessData Corp.

    mailto:staym@accessdata.com