NIST 800-53 REV 5 • SYSTEM AND SERVICES ACQUISITION
SA-8(27) — Human Factored Security
Implement the security design principle of human factored security in {{ insert: param, sa-08.27_odp }}.
CMMC Practice Mapping
No direct CMMC mapping
NIST 800-171 Mapping
No direct NIST 800-171 mapping
Related Controls
No related controls listed
Supplemental Guidance
The principle of human factored security states that the user interface for security functions and supporting services is intuitive, user-friendly, and provides feedback for user actions that affect such policy and its enforcement. The mechanisms that enforce security policy are not intrusive to the user and are designed not to degrade user efficiency. Security policy enforcement mechanisms also provide the user with meaningful, clear, and relevant feedback and warnings when insecure choices are being made. Particular attention is given to interfaces through which personnel responsible for system administration and operation configure and set up the security policies. Ideally, these personnel are able to understand the impact of their choices. Personnel with system administrative and operational responsibilities are able to configure systems before start-up and administer them during runtime with confidence that their intent is correctly mapped to the system’s mechanisms. Security services, functions, and mechanisms do not impede or unnecessarily complicate the intended use of the system. There is a trade-off between system usability and the strictness necessary for security policy enforcement. If security mechanisms are frustrating or difficult to use, then users may disable them, avoid them, or use them in ways inconsistent with the security requirements and protection needs that the mechanisms were designed to satisfy.
Practitioner Notes
Human-factored security means designing security controls that work with human behavior rather than against it. If a security control requires perfect human behavior to be effective, it will fail.
Example 1: Replace complex password requirements with passphrase policies and MFA. 'FourRandomWordsAreEasy!' is both more secure and easier to remember than 'P@ssw0rd123!'. Combine with MFA so that even if the passphrase is compromised, the account is still protected.
Example 2: Use single sign-on (SSO) to reduce the number of credentials users must manage. Every separate login is a security failure point — users will reuse passwords, write them on sticky notes, or choose weak ones. Federate all applications through Azure AD SSO so users authenticate once with strong MFA and everything else follows automatically.