Definition
Physical changes to a computer enclosure which reduce the ability for agents or the environment to affect the contained computer system.
How it works
System designers or operators make physical changes to a computer enclosure which reduce the ability for agents or the environment to affect the contained computer system. These additions to the enclosure may be of various materials to reduce the effects of heat, gases, vibration, or agent access.
Considerations
- Use asset inventory tools to track physical equipment and monitor both people and devices for access control.
- Consider relevant regulations to ensure enclosures are in compliance.
- Properly hardened enclosures should be installed and maintained to ensure they are operable and free of tampering. Access to these enclosures is controlled through physical barriers, such as locks and bolts, and may include tamper-evident hardware.
- Records should be maintained concerning maintenance performed, access, and any possible tampering marks or associated incidents.
Implementation perspective
Physical Enclosure Hardening should be treated as a technical defensive capability rather than a product checkbox. In practice, teams should define the protected scope, the conditions under which the technique acts, and the observable evidence that demonstrates the intended behavior. For this technique, likely engineering context includes the relevant system, activity, and evidence sources.
Use the technique to increase the effort, prerequisites, or constraints an adversary must overcome before exploitation or misuse succeeds.
Questions to ask
- Which component, configuration, credential, interface, or behavior is being hardened?
- What secure baseline or policy defines the intended state?
- How are exceptions approved, time-limited, and reviewed?
- How is the hardened state verified after deployment and significant change?
Evidence and validation
- Approved hardening standards and configuration baselines
- Automated configuration or integrity assessment results
- Exception records with owners, rationale, and expiration dates
- Test results demonstrating that the intended restriction is enforced
Common failure patterns
- A secure setting is documented but not enforced consistently across the environment.
- Hardening breaks required functions and is permanently weakened through undocumented exceptions.
- Teams measure deployment of a product rather than verification of the hardened condition.
This implementation perspective is original Bare Metal Cyber educational content. It does not replace the official D3FEND definition or establish that a specific product implements the technique.
Technique hierarchy
Top-level family
Parent techniques
Direct child techniques
None listed at this level.
Artifacts and ontology entities
These relationships describe how D3FEND connects a defensive technique to artifacts or other ontology entities. They describe graph semantics, not a product certification.
Explicit technique relationships
Authoritative sources
- Open this technique on the official D3FEND website ↗
- Open the official ontology resources ↗
- REGULATORY GUIDE 5.12 GENERAL USE OF LOCKS IN THE PROTECTION AND CONTROL OF: FACILITIES, RADIOACTIVE MATERIALS, CLASSIFIED INFORMATION, CLASSIFIED MATTER, AND SAFEGUARDS INFORMATION ↗U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REGULATORY RESEARCH · U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REGULATORY RESEARCH · GuidelineReference
- Guide to Operational Technology (OT) Security ↗NIST · InternetArticleReference
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