This guideline focuses on the authentication of subjects who interact with government information systems over networks to establish that a given claimant is a subscriber who has been previously authenticated. The result of the authentication process may be used locally by the system performing the authentication or asserted elsewhere in a federated identity system. This document defines technical requirements for each of the three authenticator assurance levels. The guidelines are not intended to constrain the development or use of standards outside of this purpose. This publication supersedes NIST Special Publication (SP) 800-63B.

This guideline focuses on identity federations and the use of assertions to implement them. Federation allows a given credential service provider to provide authentication attributes and (optionally) subscriber attributes to a number of separately administered relying parties. Similarly, relying parties may use more than one credential service provider. These guidelines are not intended to constrain the development or use of standards outside of this purpose. This publication supersedes NIST Special Publication (SP) 800-63C.