Hi

here my idea for a "random prime" number generator. Like Phil's

random 512 bit string idea mine works like this...

let x be a 128 bit binary string starting with 1 and having a

subsequent 127 random bits (using a random number generator).

Next let f=x^4-x-1 so that f has the required 512 bits.

Calculate x^(f-1) mod f. If this is 1 then we have a "charateristic

pseudoprime" (after much searching I have not found a composite one)

which is also automatically a "symmetric pseudoprime" (but unlike the

classical methods only requires one exponential calculation).

Perhaps someone can give an estimate of the number of possible primes

that can be found for this 127 bit domain.

Paul