High Assurance Guard (HAG)

Primary definition

An enclave boundary protection device that controls access between a local area network that an enterprise system has a requirement to protect, and an external network that is outside the control of the enterprise system, with a high degree of assurance. (SP 800-32) (NISTIR) A guard that has two basic functional capabilities: a Message Guard and a Directory Guard. The Message Guard provides filter service for message traffic traversing the Guard between adjacent security domains. The Directory Guard provides filter for directory access and updates traversing the Guard between adjacent security domains. (CNSSI-4009) (NISTIR)

Also known asHAG · High Assurance Boundary Guard · High Assurance Network Guard · High Assurance Cross Domain Guard
1 sources cited4 related termsReviewed by Martins Ogundare · Aug 10, 2026
The Cyber GlossaryView source

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TCG

An enclave boundary protection device that controls access between a local area network that an enterprise system has a requirement to protect, and an external network that is outside the control of the enterprise system, with a high degree of assurance. (SP 800-32) (NISTIR) A guard that has two basic functional capabilities: a Message Guard and a Directory Guard. The Message Guard provides filter service for message traffic traversing the Guard between adjacent security domains. The Directory Guard provides filter for directory access and updates traversing the Guard between adjacent security domains. (CNSSI-4009) (NISTIR)

The Cyber Glossary · 2024

Cite this term

Permanent URL · stable across revisions
Election Security Glossary. (2026). High Assurance Guard (HAG). In Election Security Glossary. Retrieved September 2, 2026, from https://electionsecurityglossary.com/glossary/high-assurance-guard-hag

Sources

1 cited · last checked Aug 10, 2026

01

The Cyber Glossary
The Cyber Glossary

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