Date Added: Feb 2012
A cryptographic hash function is a function which maps an input of arbitrary length to an output of fixed length. It should satisfy at least collision-, preimage- and second-preimage resistance and is one of the most important primitives in cryptography. In recent years, most of the functions in the widely used MD4-family have been successfully attacked in several ways which has stimulated researchers to look for alternatives. Block cipher based constructions seem promising since they are very well known - they even predate the MD4-approach.