List of one-shot passwords

[Matthew J Ghio <mg5n+@andrew.cmu.edu>]

 "Alan (Gesture Man) Wexelblat" <wex@media.mit.edu> wrote:

> It seems to me that a simpler solution than challenge-response would
> be to emultate the tear-sheet crypto systems and just have a series of
> one-shot passwords generated.  Each time you log in, it requires the
> next password from the sheet, so capturing the old one does no good
> (just as breaking the one-time codes from tear sheets doesn't help).
>
> Now if I could just figure out a simple way to do this on UNIX...

You can use a sequential PRNG to do this, and then add a scrambling
system to the output (to confuse anyone trying to break the pattern).  I
once wrote a program to do this (just for experimentation, and not in
UNIX...).