This work presents recent developments in hashing algorithm design. 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 without secrecy. Covering all practical and theoretical issues related to the design of secure hashing algorithms the book is self contained; it includes an extensive bibliography on the topic.