Changes in Federal Information Processing Standard (FIPS) 180-4, Secure Hash Standard
Quynh H. Dang
This paper describes the changes between FIPS 180-3 and FIPS 180-4. FIPS 180-4 specifies two new secure cryptographic hash algorithms: SHA-512/224 and SHA-512/256; it also includes a method for determining initial value(s) for any future SHA-512-based hash algorithm(s). FIPS 180-4 also removes a requirement for the execution of the message length encoding operation.