A case for a parallelizable hash

On November 2, 2007, NIST (United States National Institute of Standards and Technology) announced an initiative to design a new secure hash function for this century, to be called SHA-3. The competition will be open and it is planned to conclude in 2012. These developments are quite similar to the recent history of symmetric block ciphers— breaking of the DES (Data Encryption Standard) and emergence of the AES (Advanced Encryption Standard) in 2001 as the winner of a multiyear NIST competition. In this paper we make a case that parallelizability should be one of the properties sought in the new SHA-3 design. We present a design concept for a parallelizable hash function called PHASH based on a block cipher, and we discuss PHASH’s performance and security.