Searching for uncopyable key made of sparkles in plastic

[Michael Shields]

In message <20030902233422.81119.qmail at web40609.mail.yahoo.com>,
Morlock Elloi <morlockelloi at yahoo.com> wrote:
> Anything that regular camera captures the attacker can also capture and
> reproduce it for the benefit of the camera.

Please read the paper.  What's sent is not a picture of the token, but
a hash of a picture of the pattern produced by a laser shining through
the token.  Because the laser scatters through the token in three
dimensions it is difficult to model or reproduce the token.  By
varying the angle of the laser you can produce a large number of
possible patterns, too many to be stored -- it's claimed this can be
as much as 7 TB of data.  So you can have a useful level of security
even with untrusted token readers, and an extremely high level of
security with trusted token readers.
-- 
Shields.