Knowledge is Power

Sitewide Search

Search Bare Metal Cyber

Search courses, individual lessons, wiki entries, books, podcasts, magazine articles, Daily Cyber News, and Darwin.

MITRE D3FEND™ Learning Center

D3-ET — Encrypted Tunnels

Encrypted encapsulation of routable network traffic.

1NIST mapping
2Mitigation mappings
1Parent technique
1Related artifact

Isolate · D3FEND ontology 1.6.0 · Active

Open official technique ↗
Official D3FEND definition

Definition

Encrypted encapsulation of routable network traffic.

Bare Metal Cyber interpretation

Implementation perspective

Encrypted Tunnels 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 create a logical or physical boundary that limits access, execution, communication, or movement.

Questions to ask

  • What is being isolated, from whom or what, and under which conditions?
  • Which flows or operations remain explicitly allowed across the boundary?
  • What happens when the isolation mechanism fails or loses policy context?
  • How is the boundary tested for alternate paths, bypasses, and unintended dependencies?

Evidence and validation

  • Architecture and data-flow diagrams showing the isolation boundary
  • Policy, rule, or configuration exports from enforcing components
  • Tests of allowed, denied, and failure-state behavior
  • Monitoring evidence for boundary violations and policy changes

Common failure patterns

  • The intended boundary has undocumented alternate paths or inherited trust relationships.
  • Rules accumulate without ownership, review, or removal of obsolete exceptions.
  • Isolation is assumed from network location while application, identity, or management paths remain open.

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.

Ontology hierarchy

Technique hierarchy

Top-level family

Parent techniques

Direct child techniques

None listed at this level.

D3FEND graph relationships

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

isolatesIntranet Network
Curated semantic mapping

NIST SP 800-53 relationships

The relation label is preserved from the D3FEND ontology. It is not converted into a claim that the control automatically implements or validates this technique.

Curated D3FEND mapping

ATT&CK Enterprise mitigation relationships

These links come from the D3FEND ontology’s ATT&CK mitigation mapping. They help users navigate between the knowledge bases and do not guarantee mitigation effectiveness.

Source record

Authoritative sources