Cryptographic hash functions

Abstract Hash functions were introduced in cryptology in the late seventies as a tool to protect the authenticity of information. Soon it became clear that they were a very useful building block to solve other security problems in telecommunication and computer networks. This paper sketches the history of the concept, discusses the applications of hash functions, and presents the approaches that have been followed to construct hash functions. In addition, it tries to provide the information which is necessary to choose a practical hash function. An overview of practical constructions and their performance is given and some attacks are discussed. Special attention is paid to standards dealing with hash functions.