Unidirectional Gateway vs Air Gap

Side-by-side matrix

Why the distinction matters

A unidirectional gateway permits one-way mediated data flow; an air gap is a claimed absence of direct network connectivity. Systems and institutions fail when one side is used as a shortcut for the other. The distinction determines what evidence is collected, who may decide, what can be appealed, and which failure modes must be controlled.

Common failure caused by conflation

Calling a one-way connection an air gap or assuming either guarantees trustworthy data.

This error can create false confidence, unauthorized status, misattributed liability, silent loss of correction rights, or an operational claim based only on descriptive material.

Implementation consequences

• Use different fields, identifiers, and claim-status records for each side.
• Require separate evidence and currentness checks.
• Do not let a user-interface label silently merge the categories.
• Preserve correction and supersession history for both.
• Route decisions to the ecosystem authority that owns the relevant function.

Legal consequences

Safety, reliability, nuclear, grid, occupational, environmental, and emergency obligations can impose different priorities and decision authorities on the same event.

Technical evidence can inform a legal decision but cannot replace jurisdiction, legal basis, procedural authority, due process, or remedy. Conversely, a lawful decision does not make the underlying technical record accurate if the evidence is stale or defective.

Examples

1. A valid signature demonstrates control over a key and payload integrity; it does not establish the truth of every signed statement.
2. A registry can record a citizenship decision; the registry operator does not thereby acquire constitutional power to create citizenship.
3. A static release can show that software exists; it does not prove the service is currently operating.

Sources

• Consequence-driven Cyber-informed Engineering — Idaho National Laboratory; INL CCE program page; Official laboratory methodology description. Exact claim-support entries: 2. Revalidated 2026-08-15T16:00:00Z.
• NIST SP 800-82 Revision 3 — Guide to Operational Technology Security — National Institute of Standards and Technology; NIST SP 800-82 Rev. 3; NIST Final Publication. Exact claim-support entries: 1. Revalidated 2026-08-15T20:00:00Z.
• 10 CFR 73.54 — Protection of Digital Computer and Communication Systems and Networks — U.S. Nuclear Regulatory Commission / Electronic Code of Federal Regulations; 10 CFR 73.54, current eCFR; Federal regulation. Exact claim-support entries: 2. Revalidated 2026-08-15T16:00:00Z.

Comparison claim record

Each proposition has a stable ID, status, scope, owning route, evidence relationship, currentness qualification, correction state, and synchronized JSON record. Record completeness does not make the proposition true.