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.