DISCUSSION [NIST SP 800-171 R2]

Authenticity protection includes protecting against man-in-the-middle attacks, session hijacking, and the insertion of false information into communications sessions. This requirement addresses communications protection at the session versus packet level (e.g., sessions in service-oriented architectures providing web-based services) and establishes grounds for confidence at both ends of communications sessions in ongoing identities of other parties and in the validity of information transmitted.

NIST SP 800-77, NIST SP 800-95, and NIST SP 800-113 provide guidance on secure communications sessions.

FURTHER DISCUSSION

The intent of this practice is to ensure a trust relationship is established between both ends of a communication session. Each end can be assured that the other end is who it is supposed to be. This is often implemented using a mutual authentication handshake when the session is established, especially between devices. Session authenticity is usually provided by a security protocol enforced for a communication session. Choosing and enforcing a protocol will provide authenticity throughout a communications session.

Example

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].

Potential Considerations

Is a communications protocol used that ensures the sending and receiving parties do not change during a communications session [a]?

Are controls in place to validate the identities and information transmitted to protect against man-in-the-middle attacks, session hijacking, and insertion of false information into communications sessions [a]?

Copyright

Copyright 2020, 2021 Carnegie Mellon University and The Johns Hopkins University Applied Physics Laboratory LLC.

Copyright 2021 Futures, Inc.

This material is based upon work funded and supported by the Department of Defense under Contract No. FA8702-15-D-0002 with Carnegie Mellon University for the operation of the Software Engineering Institute, a federally funded research and development center, and under Contract No. HQ0034-13-D-0003 and Contract No. N00024-13-D-6400 with the Johns Hopkins University Applied Physics Laboratory LLC, a University Affiliated Research Center.

The view, opinions, and/or findings contained in this material are those of the author(s) and should not be construed as an official Government position, policy, or decision, unless designated by other documentation.

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