[tomesco]

There exist certain classes of prime numbers that should not be used for some cryptographic operations because algorithms exist that reduce the computation required for factoring attacks. This more often applies to cases where smaller primes are applied. Sources for this king of knowledge are mathematics or cryptography textbooks.

For other cryptographic operations, almost any sufficiently large prime can be used. Even a 50% reduction on a computation that will take trillions of years, has no practical impact.