Re: [PEN-TEST] Strength of RSA keys -vs- length (was Re: Places tofind crypto ...)

[Clem Colman <clem () COLMANCOMM COM>]

Sorry Al, probably looking to kill this threah huh...

Just a quick note.  The recent 512 bit factoring effort was driven by Stage
10 of Simon Singh's Code Book Challenges.

The really notable thing about the team of Swedish researchers was that they
did the factorization, formerly thought to require a supercomputer, on a
quad processor Alpha.

Links:
http://codebook.org/codebook_solution.pdf

Cracking symmetric algorithms is a linearly scalable problem.  eg An
exhaustive key space of a 58 bit key will take 4 times as many CPU time
units than 56 bit.  Solving a public/private key modulus is not a linearly
scalable problem (at least not with current techniques).  To say that 1024
bit keys can be factored in 2^512 times as many CPU time units is not
correct.

Previous notes about crypto on this list are very important.  Once you
encryption reaches a certain strength it becomes far more feasible for a
third party to pursue another avenue of compromise to obtain the
information.

Cheers,
Clem.