Security and Privacy Attributes

Dynamic association of attributes is appropriate whenever the security or privacy characteristics of information change over time. Attributes may change due to information aggregation issues (i.e., characteristics of individual data elements are different from the combined elements), changes in individual access authorizations (i.e., privileges), changes in the security category of information, or changes in security or privacy policies. Attributes may also change situationally.

The content or assigned values of attributes can directly affect the ability of individuals to access organizational information. Therefore, it is important for systems to be able to limit the ability to create or modify attributes to authorized individuals.

Maintaining the association and integrity of security and privacy attributes to subjects and objects with sufficient assurance helps to ensure that the attribute associations can be used as the basis of automated policy actions. The integrity of specific items, such as security configuration files, may be maintained through the use of an integrity monitoring mechanism that detects anomalies and changes that deviate from "known good" baselines. Automated policy actions include retention date expirations, access control decisions, information flow control decisions, and information disclosure decisions.

Systems, in general, provide the capability for privileged users to assign security and privacy attributes to system-defined subjects (e.g., users) and objects (e.g., directories, files, and ports). Some systems provide additional capability for general users to assign security and privacy attributes to additional objects (e.g., files, emails). The association of attributes by authorized individuals is described in the design documentation. The support provided by systems can include prompting users to select security and privacy attributes to be associated with information objects, employing automated mechanisms to categorize information with attributes based on defined policies, or ensuring that the combination of the security or privacy attributes selected is valid. Organizations consider the creation, deletion, or modification of attributes when defining auditable events.

System outputs include printed pages, screens, or equivalent items. System output devices include printers, notebook computers, video displays, smart phones, and tablets. To mitigate the risk of unauthorized exposure of information (e.g., shoulder surfing), the outputs display full attribute values when unmasked by the subscriber.

Maintaining attribute association requires individual users (as opposed to the system) to maintain associations of defined security and privacy attributes with subjects and objects.

To enforce security and privacy policies across multiple system components in distributed systems, organizations provide a consistent interpretation of security and privacy attributes employed in access enforcement and flow enforcement decisions. Organizations can establish agreements and processes to help ensure that distributed system components implement attributes with consistent interpretations in automated access enforcement and flow enforcement actions.

The association of security and privacy attributes to information within systems is important for conducting automated access enforcement and flow enforcement actions. The association of such attributes to information (i.e., binding) can be accomplished with technologies and techniques that provide different levels of assurance. For example, systems can cryptographically bind attributes to information using digital signatures that support cryptographic keys protected by hardware devices (sometimes known as hardware roots of trust).

A regrading mechanism is a trusted process authorized to re-classify and re-label data in accordance with a defined policy exception. Validated regrading mechanisms are used by organizations to provide the requisite levels of assurance for attribute reassignment activities. The validation is facilitated by ensuring that regrading mechanisms are single purpose and of limited function. Since security and privacy attribute changes can directly affect policy enforcement actions, implementing trustworthy regrading mechanisms is necessary to help ensure that such mechanisms perform in a consistent and correct mode of operation.

The content or assigned values of security and privacy attributes can directly affect the ability of individuals to access organizational information. Thus, it is important for systems to be able to limit the ability to create or modify the type and value of attributes available for association with subjects and objects to authorized individuals only.