Canonical Example: Conditional Confidentiality as Compositional Trust

Why This Example

Conditional confidentiality is:

  • necessary for high-trust coordination (without it, information sharing is all-or-nothing),
  • structurally fragile (boundaries are violated by implementation error, not only by intent),
  • symmetric across human and autonomous systems,
  • diagnostic of undeclared dependency.

If this case cannot be explained by the core invariant, the theory is incomplete.

Baseline (Low Trust Regime)

Human society (HTS)

In a private equity transaction under low trust, all parties retain full access to sensitive information.

  • Every actor verifies independently.
  • Information sharing is unrestricted.
  • Coordination is slow and expensive.
  • Risk is bounded by exhaustive verification.

Autonomous system (HTAS)

All components can read global state.

  • Every module revalidates inputs.
  • Strong consistency is enforced everywhere.
  • Throughput is low.
  • Safety is maintained by comprehensive verification.

No trust assumptions are made. Verification cost is paid continuously.

Introducing a Trust Assumption

Trust assumption

Sensitive information will be accessed only by designated recipients, only for specified purposes, and will not influence outputs beyond declared interfaces.

HTS instantiation

Clean teams:

  • A restricted subgroup receives confidential data.
  • Outputs are summarized and sanitized before release.
  • Other parties rely on the process without accessing raw data.

HTAS instantiation

Scoped computation:

  • Secrets are accessible only via capability grants.
  • Outputs are constrained by interface contracts.
  • Other components rely on results without inspecting internals.

This assumption reduces coordination and verification cost.

Efficiency Gain

  • Information bandwidth increases (more data flows to decision-makers).
  • Decision latency decreases (fewer verification round-trips).
  • Global coordination becomes feasible (parties can act on shared conclusions).
  • Enforcement shifts from continuous monitoring to boundary control.

High trust regime emerges locally.

Failure Mode (Undeclared Dependency)

Violation

Confidential information influences behavior beyond its declared scope.

HTS collapse

  • Insider trading, information misuse, or inadvertent disclosure.
  • Clean team outputs are no longer trusted.
  • Process credibility collapses.
  • Reversion to universal disclosure controls or deal termination.

HTAS collapse

  • Side-channel leakage, capability misuse, or privilege escalation.
  • Downstream components receive tainted inputs.
  • Trust in module outputs collapses.
  • System reverts to exhaustive verification or component isolation.

Local violation propagates to global trust loss.

Diagnosis via Core Invariant

The governing invariant states:

Trust assumptions do not introduce coupling whose violation propagates beyond the scope of the assumption.

Failure occurred because:

  1. Scope violation: the trust assumption (confidentiality) was applied, but its boundary was not enforced at all influence paths.
  2. Undeclared dependency: information flowed through channels not covered by the assumption (side channels, implicit state, unaudited outputs).
  3. Propagation: local misuse affected components that had no knowledge of the original assumption.

The system violated failure localization: a violation in one context invalidated trust in unrelated contexts.

Architectural Repair

Required constraint

Confidential data must influence the system only through interfaces that explicitly declare and bound that influence.

HTS repair

  • Legal firewalls with defined liability.
  • Auditable clean team procedures with output review.
  • Sanctions for boundary violation.
  • Information summaries that are auditably limited (demonstrably no raw data leakage).

HTAS repair

  • Noninterference guarantees enforced by type system or runtime monitor.
  • Capability discipline: secrets accessible only through revocable, scoped grants.
  • Information flow control: taint tracking or formal verification of output constraints.
  • Verifiable computation boundaries: cryptographic attestation or reproducible builds.

Trust becomes compositional: local assumptions compose without introducing global fragility.

Generalization

This pattern recurs in any system where:

  • efficiency depends on assuming compliant behavior within a scope,
  • verification is deferred to boundaries rather than performed continuously,
  • violations must remain contained to preserve unrelated interactions.

The structural requirements are:

  1. Scoped assumptions: every trust assumption declares its domain.
  2. Interface enforcement: influence paths are explicit and auditable.
  3. Failure localization: violations trigger response within scope, not global collapse.
  4. Reversion capability: the system can contract to stricter verification without losing continuity.

Conditional confidentiality is a canonical instance because it makes these requirements visible: the boundary between "knows" and "does not know" is precise, and violations are often detectable. Systems that handle this case correctly have the structure to handle analogous trust assumptions elsewhere.