Information system authenticators include, for example, tokens, PKI certificates, biometrics, passwords, and key cards. Users take reasonable measures to safeguard authenticators including maintaining possession of their individual authenticators, not loaning or sharing authenticators with others, and reporting lost or compromised authenticators immediately. For password-based authentication, the information system: (i) protects passwords from unauthorized disclosure and modification when stored and transmitted; (ii) prohibits passwords from being displayed when entered; (iii) enforces password minimum and maximum lifetime restrictions; and (iv) prohibits password reuse for a specified number of generations. For PKI- based authentication, the information system: (i) validates certificates by constructing a certification path to an accepted trust anchor; (ii) establishes user control of the corresponding private key; and (iii) maps the authenticated identity to the user account. In accordance with OMB policy and related E-authentication initiatives, authentication of public users accessing federal information systems (and associated authenticator management) may also be required to protect nonpublic or privacy-related information. FIPS 201 and Special Publications 800-73, 800-76, and 800-78 specify a personal identity verification (PIV) credential for use in the unique identification and authentication of federal employees and contractors. NIST Special Publication 800-63 provides guidance on remote electronic authentication.