[Superseded by FIPS 186-1 (December 15, 1998): http://www.nist.gov/manuscript-publication-search.cfm?pub_id=917974
] This standard specifies a Digital Signature Algorithm (DSA) which can be used to generate a digital signature. Digital signatures are used to detect unauthorized modifications to data and to authenticate the identity of the signatory. In addition, the recipient of signed data can use a digital signature in proving to a third party that the signature was in fact generated by the signatory. This is known as nonrepudiation since the signatory cannot, at a later time, repudiate the signature. Change Notice 1: Changes made to i) Appendix 3.2 Algorithm for Precomputing one or more k and r Values, and ii) Appendix 5, Example of the DSA (changed for use with FIPS 180-1, Secure Hash Standard).