Quote:
Originally Posted by xilman
If we could calculate x! mod N in polynomial time it could be used to produce a Ptime factoring algorithm. Once more, no such algorithm has been found yet neither has it been proved that an algorithm can not exist.

Hans Riesel also thought so, and mentioned this idea in one of his books. When I pointed this out in sci.crypt back in 1998, Bob said the idea was 'unconvincing'. Nothing has happened recently that gives anyone reason to change that view, unless you can take the AKS primality test as cause for hope that hard problems in number theory are susceptible to solution using simple tools.
jasonp