This work presents recent developments in hashing algorithmdesign. Hashing is the process of creating a short digest(i.e., 64 bits) for a message of arbitrary length, for exam-ple 20 Mbytes. Hashing algorithms were first used for sear-ching records in databases; they are central for digital si-gnature applications and are used for authentication withoutsecrecy. Covering all practical and theoretical issuesrelated to the design of secure hashing algorithms the bookis self contained; it includes an extensive bibliography onthe topic.