NIST 800-53 REV 5 • SYSTEM AND COMMUNICATIONS PROTECTION
SC-8 — Transmission Confidentiality and Integrity
Protect the {{ insert: param, sc-08_odp }} of transmitted information.
Supplemental Guidance
Protecting the confidentiality and integrity of transmitted information applies to internal and external networks as well as any system components that can transmit information, including servers, notebook computers, desktop computers, mobile devices, printers, copiers, scanners, facsimile machines, and radios. Unprotected communication paths are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of information can be accomplished by physical or logical means. Physical protection can be achieved by using protected distribution systems. A protected distribution system is a wireline or fiber-optics telecommunications system that includes terminals and adequate electromagnetic, acoustical, electrical, and physical controls to permit its use for the unencrypted transmission of classified information. Logical protection can be achieved by employing encryption techniques. Organizations that rely on commercial providers who offer transmission services as commodity services rather than as fully dedicated services may find it difficult to obtain the necessary assurances regarding the implementation of needed controls for transmission confidentiality and integrity. In such situations, organizations determine what types of confidentiality or integrity services are available in standard, commercial telecommunications service packages. If it is not feasible to obtain the necessary controls and assurances of control effectiveness through appropriate contracting vehicles, organizations can implement appropriate compensating controls.
Practitioner Notes
Data in transit — emails, file transfers, web traffic, database queries — must be protected from eavesdropping and tampering. If someone intercepts your network traffic, they should not be able to read or modify it.
Example 1: Require TLS 1.2 or higher for all web traffic by configuring your web servers and load balancers to reject connections using older protocols. Use a GPO to configure Windows systems to disable TLS 1.0 and 1.1 in the registry.
Example 2: In Microsoft 365, enable encryption for all email in transit by verifying that your Exchange Online connectors enforce TLS. Go to Exchange Admin Center > Mail Flow > Connectors and confirm that "Reject if TLS is not available" is enabled for partner organizations handling sensitive data.