Traditional cryptography: Autokey password, permutation password, by Charles Wheatstone, multi-letter substitution password, Hill password, Virginia password, substitution password, Caesar password, ROT 13, affine password, Atbash password, transposition password, Scytale.

Grille password, VIC password (a complicated manual password, which was used by at least one Soviet spy in the early 1950s and was very safe at that time) Modern encryption: password hash function (message digest algorithm, MD algorithm) password hash function.

Message authentication code

Keyed hash message verification code

Nisi chooses MAC.

HMAC (selected by Nishi MACISO/FIPS IEC 9797- 1 and IETF RFC)

TTMAC is also called dual-track MAC(nessie selection MAC；; Leuven Belgium; Debis ag (Germany)

UMAC (Nixi select MAC Intel, Renault, IBM, Technion and. UCal Davis)

MD5 (one of a series of message digest algorithms, proposed by Professor Ron Rivest of MIT; 128 bit abstract)

Public/private key encryption algorithm (also known as asymmetric key algorithm) public/private key signature algorithm private key algorithm (also known as symmetric key algorithm)