NIST SP 800-53 Rev. 5 · SC-28

Protection of Information at Rest

US National Institute of Standards and Technology (NIST) · cited in 194 of our lessons

What it asks for. The confidentiality and/or integrity of defined information at rest must be protected.

In practice. Typical measures are full-disk encryption on laptops and mobile devices, encryption of databases, storage and backups with properly managed keys, and access controls on storage locations. Auditors look for encryption coverage reports, key management procedures and evidence that sensitive data stores are identified. ISO/IEC 27001 cryptography controls and GDPR security of processing make similar demands. Data classification helps decide where stronger options, such as customer-managed keys or application-level encryption, are justified.

Common gaps. Encryption is often switched on with provider-managed keys without considering who can access the keys. Data copies in exports, file shares and analytics platforms are frequently overlooked. Encryption at rest also does little against an attacker who uses a legitimate account, so it must be paired with access control.

Open SP 800-53 at NIST

The official text

Protect the [Selection: confidentiality; integrity] of the following information at rest: [Assignment: organization-defined information at rest]. Discussion: Information at rest refers to the state of information when it is not in process or in transit and is located on system components. Such components include internal or external hard disk drives, storage area network devices, or databases. However, the focus of protecting information at rest is not on the type of storage device or frequency of access but rather on the state of the information. Information at rest addresses the confidentiality and integrity of information and covers user information and system information. System-related information that requires protection includes configurations or rule sets for firewalls, intrusion detection and prevention systems, filtering routers, and authentication information. Organizations may employ different mechanisms to achieve confidentiality and integrity protections, including the use of cryptographic mechanisms and file share scanning. Integrity protection can be achieved, for example, by implementing write-once-read-many (WORM) technologies. When adequate protection of information at rest cannot otherwise be achieved, organizations may employ other controls, including frequent scanning to identify malicious code at rest and secure offline storage in lieu of online storage.

From NIST SP 800-53 Rev. 5, a work of the US government in the public domain.

Lessons that cite it

Real incidents where this item mattered: the latest 12 of 194.