The operating system must protect the confidentiality and integrity of all information at rest.

Information at rest refers to the state of information when it is located on a secondary storage device (e.g., disk drive and tape drive, when used for backups) within an operating system. This requirement addresses protection of user-generated data, as well as operating system-specific configuration data. Organizations may choose to employ different mechanisms to achieve confidentiality and integrity protections, as appropriate, in accordance with the security category and/or classification of the information.