Although this has been extensively discussed around here, I'm curious whether my approach makes sense, or I should just stick to "the standard version".
I'm implementing some homomorphic encryption primitives (Paillier, Okamoto–Uchiyama etc) and, at the moment, I'm using GMP as the big number library (this may change in the future). GMP has a function called
mpz_nextprime and I generate random numbers, after which I call this function on them, to get prime numbers. Is this a good approach? The other alternative would be to just generate random numbers in a loop, until
mpz_probab_prime_p(number, 10) says that they are prime. This latter approach seems rather wasteful though, from a programmer's point of view.
How do you generate prime numbers with GMP or OpenSSL (or other crypto libraries like cryptlib, crypto++, etc)? I am unsure how the
mpz_nextprime function works or if other libraries provide such functionality... Ideally, I should be able to just swap various big number libraries in my implementation, without changing the prime generator wrapper.