blaine <[EMAIL PROTECTED]> wrote: > > For my Network Security class we are designing a project that will, >among other things, implement a Diffie Hellman secret key exchange. >The rest of the class is doing Java, while myself and a classmate are >using Python (as proof of concept). I am having problems though with >crunching huge numbers required for calculations. As an alternative I >can use Java - but I'd rather have a pure python implementation. The >problem is that Python takes a very long time (I haven't had it finish >yet)
And it won't. Ever. Well, actually, it will finish when it crashes. >... > G = >long(2333938645766150615511255943169694097469294538730577330470365230748185729160097289200390738424346682521059501689463393405180773510126708477896062227281603) > P = >long(7897383601534681724700886135766287333879367007236994792380151951185032550914983506148400098806010880449684316518296830583436041101740143835597057941064647) > > a = self.rand_long(1) # 512 bit long integer > > A = (G ** a) % P # G^a mod P > >###### END ##### >The above code takes a very long time. We all know the proper answer (use 3-arg math.pow). However, Paul Rubin's suggested to figure out how large (G ** a) prompted me to go do just that. That expression is not computable on any computer on Earth today. It is a number requiring 7 x 10**156 bits. Consider that a terabyte hard disk today only includes 9 x 10**12 bits. Also consider that, by rough estimate, there are approximately 10**80 atoms in the known universe today... -- Tim Roberts, [EMAIL PROTECTED] Providenza & Boekelheide, Inc. -- http://mail.python.org/mailman/listinfo/python-list
