Proposals for Iterated Hash Functions

The past few years have seen an increase in the number of attacks on cryptographic hash functions. These include attacks directed at specific hash functions, and generic attacks on the typical method of constructing hash functions. In this paper we discuss possible methods for protecting against some generic attacks. We also give a concrete proposal for a new hash function construction, given a secure compression function which, unlike in typical existing constructions, is not required to be resistant to all types of collisions. Finally, we show how members of the SHA-family can be turned into constructions of our proposed type.