SC.L2-3.13.15
Communications Authenticity
Source and approval
CMMC Assessment Guide — Level 2 · Revision 2.13
Publisher approved · Complete cited source edition 2026-10-31
Read the official guideSee SC.L2-3.13.15 in the reference catalog with its NIST cross-references
Official requirement
Protect the authenticity of communications sessions.
Assessment objectives
a. the authenticity of communications sessions is protected.
Implementation guidance
Editorial examples to help you plan. Adapt them to your environment; the official requirement and objectives remain authoritative.
In plain language
Protect the authenticity of communications sessions.
Implementation example
Example from the source assessment guide (not a mandatory implementation): You are a system administrator responsible for ensuring that the two -factor user authentication mechanism for the servers is configured correctly . You purchase and maintain the digital certificate and replace it with a new one before the old one expires. You ensure the TLS configuration settings on the web servers, VPN solution, and other components that use TLS are correct, using secure settings that address risks against attacks on the encrypted sessions [a].
Evidence examples
Examples suggested by the source guide (not an exhaustive or mandatory checklist): System and communications protection policy; procedures addressing session authenticity; system security plan; system design documentation; system configuration settings and associated documentation; system audit logs and records; other relevant documents or records
Common mistakes
Protecting confidentiality while overlooking whether the communicating party or session is authentic.