cryptography¶ Glossary¶ AES: Advanced Encryption Standard, a specification for the encryption of electronic data established by NIST in 2001. Supersedes DES. Symmetric key algorithm. HMAC: hash-based message authentication code. MAC: message authentication code. nonce: an arbitrary number that can be used just once in a cryptographic communication. SHA: Secure Hash Algorithms are a family of cryptographic hash functions published by NIST as a U.S. Federal Information Processing Standard (FIPS).