"The Secretary of Commerce has approved FIPS 180-2, Secure Hash Standard, and has determined that the standard is compulsory and binding on Federal agencies for the protection of sensitive, unclassified information.
FIPS 180-2, Secure Hash Standard, replaces FIPS 180-1, which was issued in 1992 and which specified an algorithm (SHA-1) for producing a 160-bit output called a message digest. The message digest is a condensed representation of electronic data and is used in cryptographic processes such as digital signatures and message authentication. FIPS 180-2 includes three additional algorithms, which produce 256-bit, 384-bit, and 512-bit message digests. These expanded capabilities are compatible with and support the strengthened security requirements of FIPS 197, Advanced Encryption Standard."