Bidirectional authentication that is replay-resistant is implemented.
Identify and authenticate [Assignment: organization-defined systems and system components] before establishing a network connection using bidirectional authentication that is cryptographically based and replay resistant.
Cryptographically-based and replay-resistant authentication between systems, components, and devices addresses the risk of unauthorized access from spoofing (i.e., claiming a false identity). The requirement applies to client-server authentication, server-server authentication, and device authentication (including mobile devices). The cryptographic key for authentication transactions is stored in suitably secure storage available to the authenticator application (e.g., keychain storage, Trusted Platform Module [TPM], Trusted Execution Environment [TEE], or secure element). Mandating authentication requirements at every connection point may not be practical, and therefore, such requirements may only be applied periodically or at the initial point of network connection. [SP 800-63-3] provides guidance on identity and authenticator management.