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Discussion

It was found by [4] that the Pohlig-Hellman algorithm is most efficient when p-1 has only small prime factors. In contrast, the algorithm is least efficient when where p'is also a prime and of the same order as p . For 200 digit long primes the requirements of memory are too large and thus, it is infeasible to apply the Pohlig-Hellman Algorithm to solve the discrete logarithm problem in these fields.

Another fact is important to point out. Accordding to [3] the complexity of the algorithm is O() group operations using O() bits of memory and provided that a precomputation requiring O() field operations is carried out first. This project will be compared to the results in [3], each part of the program will be analyzed independently, and then combined for an overall estimate of the complexity of the implementation. Finally, tests of the run time of the program were realized and tabulated in section 4.3 (All the tests presented in this section were performed on a 175 MHz Alpha processor with 128 Mb of RAM, unless otherwise stated).





Pedro Soria-Rodriguez
Sat Mar 16 16:13:36 EST 1996