A primality test is a method (or algorithm) to find out if a certain number is a prime number. Cryptography uses prime numbers, and needs to test if a certain number is prime. The official proof of a prime is through its primality certificate.
Simple methods[change | change source]
- Sieve of Eratosthenes: Determine if there is a number (between 2 and n, the number to test) that divides n, without a rest
- Wilson's theorem (inefficient): evaluates to -1 mod p where p is the candidate prime number
Better methods[change | change source]