Classification of Hash Functions Suitable for Real-life Systems

Abstract

Cryptographic hash functions have been widely studied and are used in many current systems. Though much re­ search has been done on the security of hash functions, system designers cannot determine which hash function is most suitable for a particular system. The main reason for this is that the current security classification does not cor­ respond very well to the security requirements of practical systems. This paper describes a new classification which is more suitable for designing real-life systems. This clas­ sification is the result of a new theoretical classification and a new qualitative classification. We show a mapping between each class and standard protocols. In addition, we show new requirements for four types of hash function for a future standard.