[Superseded by NIST SP 800-63 Ver. 1.0.1 (September 2004): http://www.nist.gov/manuscript-publication-search.cfm?pub_id=151295
] This recommendation provides technical guidance to Federal agencies implementing electronic authentication. The recommendation covers remote authentication of users over open networks. It defines technical requirements for each of four levels of assurance in the areas of identity proofing, registration, tokens, authentication protocols and related assertions.