The nist's standard for digital signatures (authenticating both a message and the signer) that was first announced in 1991. It is based on an algorithm using discrete logarithms, which is a variant of the elgamal algorithm with Schnorr's improvements. DSS's security is currently considered very strong - comparable to rsa. It is estimated that DSS's 1024-bit keys would take 1.4E16 mips-years to crack.