3.5.3: Use multifactor authentication for local and network access to privileged accounts and for network access to non-privileged accounts

Discussion

Multifactor authentication requires the use of two or more different factors to authenticate. The factors are defined as something you know (e.g., password, personal identification number [PIN]); something you have (e.g., cryptographic identification device, token); or something you are (e.g., biometric). Multifactor authentication solutions that feature physical authenticators include hardware authenticators providing time-based or challenge-response authenticators and smart cards. In addition to authenticating users at the system level (i.e., at logon), organizations may also employ authentication mechanisms at the application level, when necessary, to provide increased information security.

Access to organizational systems is defined as local access or network access. Local access is any access to organizational systems by users (or processes acting on behalf of users) where such access is obtained by direct connections without the use of networks. Network access is access to systems by users (or processes acting on behalf of users) where such access is obtained through network connections (i.e., nonlocal accesses). Remote access is a type of network access that involves communication through external networks. The use of encrypted virtual private networks for connections between organization-controlled and non-organization controlled endpoints may be treated as internal networks with regard to protecting the confidentiality of information.

[SP 800-63-3] provides guidance on digital identities.