domain security policy

A governing instrument — specifically a sub-component of a Key Management Policy — that defines the protection requirements, rules, and restrictions applicable to all cryptographic keys, metadata, and sensitive data within a bounded security domain. It "provides the rules and restrictions that allow computers [and] networks" within a domain to operate under a common protective posture. Its defining function is to enable or constrain cross-domain transfers: before any entity may send cryptographic keys or metadata to a receiver, both the sending and receiving entities must have assurance that each other's domain security policy provides at least equivalent protection. In practice, NIST uses it to specify whether a domain provides a high or low level of protection to the keys and/or metadata it processes, making the term operative primarily in cryptographic key management governance and cross-domain interoperability assessments per NIST SP 800-57.