Date Added: May 2011
Cryptographic hash functions are one of the most important primitives in cryptography. A hash function maps from inputs of arbitrary length to a binary sequence of some fixed length. A hash function usually consists of iteration of a compression function with fixed input and output length. One first designs a fixed domain compression function and then extends the domain to an arbitrary domain by iterating that function. As flaws in popular classic hash functions MD5 and SHA-1 have been discovered, NIST has launched a competition for a new hash function standard SHA-3.