Abstract
The most efficient known primality tests are probabilistic in the sense that they use randomness and may, with some probability, mistakenly classify a composite number as prime – but never a prime number as composite. Examples of this are the Miller–Rabin test, the Solovay–Strassen test, and (in most cases) Fermat's test.
This entry defines these three tests and proves their correctness. It also develops some of the number-theoretic foundations, such as Carmichael numbers and the Jacobi symbol with an efficient executable algorithm to compute it.