Primality test

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
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
Fermat's primality test
Miller-Rabin primality test

Category:Prime numbers
.