speaking of weak primes, weak exponents?

[Peter Gutmann]

coderman <coderman at gmail.com> writes:

>not a big deal or something to be concerned about?  (the speed improvement
>shown makes me think this should be a check performed for all prime selection
>in any pubkey system, even if it is unlikely)

I've also posted this to sci.crypt to see if anyone there had any comments,
both Tom St.Denis (a regular contributor and author of libtomcrypt) and David
Wagner (needs no introduction :-) comment that the chance of a random 512-bit
prime having this form is about 1/2^250, so it's not worth checking for.  See
the sci.crypt thread for more info.

Peter.