On Tue, May 30, 2006 at 09:20:59AM -0700, Geoffrey Irving wrote:
Z<r> x = N; Z<s> y = N;
As pointed out by someone else already, what if r = 2^30402457-1?
More fundamentally, encryption usually fails if the secret prime numbers are hard coded into the encryption code as template arguments. Unless you want the encryption code to recompile itself whenever it generates a new random key, that is.
Okay. I agree that it should be possible to have dynamic (or non-builtin integral) numbers for the modulo (say 'p'). One could still argue that in those cases it probably isn't necessary to work in Z_p, but well. A general library shouldn't post restrictions on practical use like that, I guess-- and you are right that a template argument would be limited to int or long long at most. The only real advantage of using a template argument is probably that you can make things faster during runtime - but as always, the algorithm used is much more important than some constant factor that one might gain there. So, I'm convinced ;). I'm okay with a library that allows the modulo to be set during runtime. -- Carlo Wood <carlo@alinoe.com>