NIST requests public comment on proposed SHA-3 cryptographic standard

The National Institute of Standards and Technology (NIST) has requested public comments on its newly proposed "Secure Hash Algorithm-3" (SHA-3) Standard, which is designed to protect the integrity of electronic messages.

The draft Federal Information Processing Standard Publication 202, SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions, specifies six permutation-based "sponge" functions based on Keccak, the winning algorithm selected from NIST's SHA-3 Cryptographic Hash Algorithm Competition. The functions include four fixed-length cryptographic hash functions, and two closely related "extendable-output" functions (XOFs). The four fixed-length hash functions provide alternatives to the SHA-2 family of hash functions specified in FIPS 180, Secure Hash Standard, which FIPS 202 will supplement. The XOFs can be specialized to hash functions, subject to additional security considerations, or used in a variety of other applications.

Cryptographic hash algorithms are a cornerstone of modern information security. They transform a digital message into a short "message digest" for use in digital signatures. Even a small change in the original message text creates a change in the digest, making it easier to detect accidental or intentional changes to the original message. Hash algorithms are used by many security applications, including random bit generation.