A physical or logical boundary that is defined for a system, domain, or enclave; within which a particular security policy or security architecture is applied.
Sources:
CNSSI 4009-2022
under security perimeter
The boundary where security controls are in effect to protect assets.
Sources:
CNSSI 4009-2022
under security perimeter
All components of an information system to be accredited by an authorizing official and excludes separately accredited systems to which the information system is connected. Synonymous with the term security perimeter defined in CNSS Instruction 4009 and DCID 6/3.
Sources:
NIST SP 800-60 Vol. 1 Rev. 1
under Accreditation Boundary
NIST SP 800-60 Vol. 2 Rev. 1
under Accreditation Boundary