Control: The information system protects the [Selection(one or more): confidentiality; integrity] of [Assignment: organisation-defined information at rest].
Protection of Information at Rest Supplemental Guidance:
This control addresses the confidentiality and integrity of information at rest and covers user information and system information. Information at rest refers to the state of information when it is located on storage devices as specific components of information systems. System-related information requiring protection includes, for example, configurations or rule sets for firewalls, gateways, intrusion detection/prevention systems, filtering routers, and authenticator content. Organisations 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. Organisations may also employ other security controls including, for example, secure off-line storage in lieu of online storage when adequate protection of information at rest cannot otherwise be achieved and/or continuous monitoring to identify malicious code at rest.
Related controls: AC-3, AC-6, CA-7, CM-3, CM-5, CM-6, PE-3, SC-8, SC-13, SI-3, SI-7.
Protection of Information at Rest Control Enhancements:
SC-28 (1) Protection of Information at Rest - Cryptographic Protection
The information system implements cryptographic mechanisms to prevent unauthorised disclosure and modification of [Assignment: organisation-defined information] on [Assignment: organisation-defined information system components].
Supplemental Guidance: Selection of cryptographic mechanisms is based on the need to protect the confidentiality and integrity of organisational information. The strength of mechanism is commensurate with the security category and/or classification of the information. This control enhancement applies to significant concentrations of digital media in organisational areas designated for media storage and also to limited quantities of media generally associated with information system components in operational environments (e.g., portable storage devices, mobile devices). Organisations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). Organisations employing cryptographic mechanisms to protect information at rest also consider cryptographic key management solutions.
SC-28 (2) Protection of Information at Rest - Off-Line Storage
The organisation removes from online storage and stores off-line in a secure location [Assignment: organisation-defined information].
Supplemental Guidance: Removing organisational information from online information system storage to off-line storage eliminates the possibility of individuals gaining unauthorised access to the information through a network. Therefore, organisations may choose to move information to off-line storage in lieu of protecting such information in online storage.