Identification and Authentication (Organizational Users)

Multi-factor authentication requires the use of two or more different factors to achieve authentication. The authentication factors are defined as follows: something you know (e.g., a personal identification number [PIN]), something you have (e.g., a physical authenticator such as a cryptographic private key), or something you are (e.g., a biometric). Multi-factor authentication solutions that feature physical authenticators include hardware authenticators that provide time-based or challenge-response outputs and smart cards such as the U.S. Government Personal Identity Verification (PIV) card or the Department of Defense (DoD) Common Access Card (CAC). In addition to authenticating users at the system level (i.e., at logon), organizations may employ authentication mechanisms at the application level, at their discretion, to provide increased security. Regardless of the type of access (i.e., local, network, remote), privileged accounts are authenticated using multi-factor options appropriate for the level of risk. Organizations can add additional security measures, such as additional or more rigorous authentication mechanisms, for specific types of access.

Multi-factor authentication requires the use of two or more different factors to achieve authentication. The authentication factors are defined as follows: something you know (e.g., a personal identification number [PIN]), something you have (e.g., a physical authenticator such as a cryptographic private key), or something you are (e.g., a biometric). Multi-factor authentication solutions that feature physical authenticators include hardware authenticators that provide time-based or challenge-response outputs and smart cards such as the U.S. Government Personal Identity Verification card or the DoD Common Access Card. In addition to authenticating users at the system level, organizations may also employ authentication mechanisms at the application level, at their discretion, to provide increased information security. Regardless of the type of access (i.e., local, network, remote), non-privileged accounts are authenticated using multi-factor options appropriate for the level of risk. Organizations can provide additional security measures, such as additional or more rigorous authentication mechanisms, for specific types of access.

Individual authentication prior to shared group authentication mitigates the risk of using group accounts or authenticators.

The purpose of requiring a device that is separate from the system to which the user is attempting to gain access for one of the factors during multi-factor authentication is to reduce the likelihood of compromising authenticators or credentials stored on the system. Adversaries may be able to compromise such authenticators or credentials and subsequently impersonate authorized users. Implementing one of the factors on a separate device (e.g., a hardware token), provides a greater strength of mechanism and an increased level of assurance in the authentication process.

Authentication processes resist replay attacks if it is impractical to achieve successful authentications by replaying previous authentication messages. Replay-resistant techniques include protocols that use nonces or challenges such as time synchronous or cryptographic authenticators.

Single sign-on enables users to log in once and gain access to multiple system resources. Organizations consider the operational efficiencies provided by single sign-on capabilities with the risk introduced by allowing access to multiple systems via a single authentication event. Single sign-on can present opportunities to improve system security, for example by providing the ability to add multi-factor authentication for applications and systems (existing and new) that may not be able to natively support multi-factor authentication.

Acceptance of Personal Identity Verification (PIV)-compliant credentials applies to organizations implementing logical access control and physical access control systems. PIV-compliant credentials are those credentials issued by federal agencies that conform to FIPS Publication 201 and supporting guidance documents. The adequacy and reliability of PIV card issuers are authorized using SP 800-79-2 . Acceptance of PIV-compliant credentials includes derived PIV credentials, the use of which is addressed in SP 800-166 . The DOD Common Access Card (CAC) is an example of a PIV credential.

Out-of-band authentication refers to the use of two separate communication paths to identify and authenticate users or devices to an information system. The first path (i.e., the in-band path) is used to identify and authenticate users or devices and is generally the path through which information flows. The second path (i.e., the out-of-band path) is used to independently verify the authentication and/or requested action. For example, a user authenticates via a notebook computer to a remote server to which the user desires access and requests some action of the server via that communication path. Subsequently, the server contacts the user via the user’s cell phone to verify that the requested action originated from the user. The user may confirm the intended action to an individual on the telephone or provide an authentication code via the telephone. Out-of-band authentication can be used to mitigate actual or suspected "man-in the-middle" attacks. The conditions or criteria for activation include suspicious activities, new threat indicators, elevated threat levels, or the impact or classification level of information in requested transactions.