Cryptoalgorithms are used in encryption, but are generally not defined as international standards. In application-independent security standards that include security mechanisms, the cryptoalgorithm is usually only described in general terms; for example, as an N-bit block algorithm.
However, there is an international register for cryptoalgorithms in which they are listed only under unique names. The registered algorithm is accompanied by parameters that describe its behavior.
The International Organization for Standardization( ISO) describes in ISO 9979 the procedure that is carried out when a cryptoalgorithm is added to the register. As defined in ISO 9979, a cryptoalgorithm transforms data into ciphertext or plaintext, using at least one secret parameter.
The selection of cryptoalgorithms is based on their future security, speed of implementation and responsiveness. Basically, a distinction is made between symmetric encryption, asymmetric encryption and digital signatures. Further aspects concern the technical environment and embedding in the infrastructures and end devices used.