On Sun, Mar 7, 2010 at 1:55 PM, Fahad Ahmad <miracles...@hotmail.com> wrote: > Dear All, > > i am writing my crytographic scheme in python, i am just a new user to it. > I have written the complete code, the only point i am stuck it is that i am > using 256 exponentiation which is normal in crytography but python just > hangs on it. > > g**x [where both g and x are 256 bit numbers , in decimal they are around > 77] > > after reading several forums, i just come to know it can be done using > numpy, i have installed python(x,y) has has both numpy and scipy installed > but i am not able to make it happen. > > any idea which library, module, or piece of code can solve this mystery :S > > sorry for bad english
A couple of things: 1) if you're working with modular exponentiation, remember that pow() takes three arguments, ie: a = 222222222222222222222222222 b = 5555555555555555555555555555 pow(a, b, 1200) will calculate the correct answer (768) very quickly, while a**b % 1200 has not terminated in the time it took me to compose this email. 2) sage has a lot of excellent tools for crypto/cryptanalysis that you may want to take a look at. 3) not saying you don't know what you're doing, but be careful when rolling your own cryptosystems- even very good cryptographers make implementation mistakes! Geremy Condra -- http://mail.python.org/mailman/listinfo/python-list
