Re: speaking of weak primes, weak exponents?

coderman <coderman@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.