DSA Signature Algorithm

In August of 1991, the U.S. National Institute of Standards and Technology (NIST) proposed a digital signature algorithm (DSA), which was adopted as a U.S. Federal Information Processing Standard (FIPS 186) subsequently.

The algorithm is a variant of the ElGamal scheme. Its security is based on the Discrete Logarithm Problem. The DSA public and private key and its procedures for signing and verification are summarised in chapter 6.3 of the script.

While DSA was specifically designed, such that it can be exported from countries regulating export of encryption soft and hardware (like the U.S. at the time when it was specified), it has been noted [Schneier1996, p. 490], that the operations involved in DSA can be used to emulate RSA and ElGamal encryption.