ISO/IEC 18032:2005 specifies methods for generating and testing prime numbers. Prime numbers are used in various cryptographic algorithms, mainly in asymmetric encryption algorithms and digital signature algorithms.

Firstly, ISO/IEC 18032:2005 specifies methods for testing whether a given number is prime. The testing methods included in ISO/IEC 18032:2005 can be divided into two groups:

• Probabilistic primality tests, which have a small error probability. All probabilistic tests described here may declare a composite to be a prime. One test described here may declare a prime to be composite.
• Deterministic methods, which are guaranteed to give the right verdict. These methods use so-called primality certificates.

Secondly, ISO/IEC 18032:2005 specifies methods to generate prime numbers. Again, both probabilistic and deterministic methods are presented.