Observation Staleness and TTL Governance

Mechanism

Each credentialed observation, at the moment it is generated, is assigned a time-to-live by its originating authority. The TTL is a signed property of the observation — bound cryptographically to the observation payload, the authoring credential, and the observation's class identifier. Downstream consumers cannot alter the TTL, extend it, or substitute their own; they can only choose to admit, reject, or further restrict.

Class-bounded TTL enforcement is the second mechanism layer. Each observation class — position, velocity, intent, identity, environmental, policy, attestation — has a maximum TTL specified by the governing class schema. An originating authority signing a position observation cannot assign a TTL longer than the position class's maximum (typically seconds for high-mobility platforms, minutes for static or low-mobility platforms). A policy observation may carry months. The class bound prevents authorities from extending freshness windows beyond what the class semantically permits, which prevents both accidental misconfiguration and adversarial extension.

At the capability evaluator, the contribution of an expired observation is zero. The evaluator does not weight expired observations down; it does not depreciate them gradually; it does not apply a confidence reduction proportional to staleness. It assigns zero contribution. The binary structure is deliberate: the capability score is a decision input, and decisions made on observations that have passed their authority-declared validity window are decisions made on data the authority has explicitly disclaimed. The evaluator's behavior reflects the disclaimer.

Freshness is audit-required at every evaluation. Each capability decision records the TTL state of every contributing observation at evaluation time — whether admitted as fresh, whether rejected as expired, what the TTL value was, what the evaluation timestamp was. The audit record is cryptographically bound to the decision so that a later auditor can reproduce the freshness state of every input observation and verify that the evaluator behaved correctly under its declared policy.

Operating Parameters

Class-bounded TTL maxima are calibrated to the temporal dynamics of the observation class. Position observations for ground vehicles in dense traffic carry TTLs of one to five seconds because the underlying state evolves on that timescale. Position observations for stationary infrastructure carry TTLs of minutes. Velocity observations carry TTLs comparable to the velocity-decorrelation time of the observed platform — milliseconds for fast-maneuvering platforms, seconds for predictable platforms. Identity and policy observations carry TTLs of hours to months because the underlying state is stable. Environmental observations span a wide range — atmospheric pressure changes slowly, but local temperature in an urban canyon evolves in minutes.

Consumer-side staleness restriction layers on top of the originator-declared TTL. A consumer that requires fresher observations than the TTL admits — a safety-critical decision that requires sub-second position freshness even if the position class permits five-second TTLs — specifies an additional staleness floor in its admissibility policy. The floor is more restrictive than the TTL but never less. The architecture establishes that the originator-declared TTL is the upper bound on admissibility lifetime; consumer policy can shrink that bound but cannot extend it.

Clock-skew tolerance is bounded and explicit. The evaluator compares the observation's expiration timestamp against its own clock, applying a tolerance interval that reflects the deployment's clock-distribution architecture (PTP-disciplined deployments tolerate microseconds; NTP-disciplined deployments tolerate tens of milliseconds; loosely-synchronized mesh deployments tolerate seconds). Observations whose expiration falls within the tolerance interval are flagged for audit but may still be admitted under explicit policy; observations clearly past the tolerance are rejected without ambiguity.

The audit-required property imposes a recording cost at every evaluation. Each contributing observation's TTL state is captured into a per-decision audit log entry that includes the observation's identifier, its TTL, the evaluation timestamp, and the freshness verdict. The log entry is signed by the evaluator and stored such that later auditors — internal compliance, regulatory authorities, post-incident reconstructors — can replay the evaluation. The recording cost is sized to the decision rate of the capability layer, not to the observation rate of the underlying mesh, which keeps it bounded even in high-volume environments.

Alternative Embodiments

Soft-expiration embodiments admit expired observations into the evaluator with explicit zero-or-marked-stale contribution rather than rejecting them at admission. The variant supports forensic analysis where the auditor wants to see which observations were considered and which were discarded, without the binary admit/reject decision obscuring the evaluator's reasoning trace.

Class-extensible TTL schemas accommodate domains the base disclosure does not enumerate. A medical-device deployment introduces a vital-signs class with sub-second TTLs; an industrial-control deployment introduces a control-loop class with millisecond TTLs; a regulatory-attestation deployment introduces a compliance-attestation class with year-scale TTLs. The schema-extension mechanism preserves the class-bounded property by requiring each new class to publish its maximum TTL through the same governance channel that publishes the base classes.

Re-attestation embodiments allow originating authorities to re-sign expiring observations with extended TTLs when the underlying state remains valid. The re-attestation is itself a credentialed act, subject to the class bound on TTL extension and producing a new audit trail entry. The variant matters for long-running observations whose underlying state genuinely persists beyond a single TTL — a policy that is reaffirmed monthly, a configuration attestation that is renewed quarterly.

Distributed-clock embodiments handle deployments where the evaluator and the originator do not share a synchronized clock. The TTL is expressed as a duration relative to a logical clock event (sequence number, epoch boundary, observation count) rather than as an absolute timestamp. The evaluator computes freshness by comparing logical clock positions rather than wall-clock timestamps. The embodiment supports submerged, polar, and deep-space deployments where wall-clock synchronization is impractical.

Probabilistic-freshness embodiments report freshness as a probability distribution rather than as a binary verdict, for use in evaluators that explicitly model uncertainty. The TTL still establishes the authority's declared validity window, but the evaluator weights contribution by an estimated probability that the underlying state remains valid — useful in environments where the authority's TTL is known to be conservative and the evaluator has independent evidence of state stability.

Composition With Composite Admissibility

The composite admissibility evaluator consumes the TTL as one of several gating factors. An observation past its TTL is rejected at admission regardless of how other factors might evaluate — a high-confidence, high-relevance, fully-credentialed observation that has expired contributes zero. An observation within its TTL passes to the next evaluation stage, where credential verification, class compatibility, consistency with prior observations, and consumer-side staleness restriction apply. The TTL is therefore the first filter in a multi-stage admissibility pipeline.

Composition with capability scoring places the TTL in the score-construction critical path. Each contributing observation supplies a contribution proportional to its weight in the relevant capability dimension, multiplied by its admissibility verdict. Expired observations multiply by zero. The capability score is therefore decomposable into the sum of fresh contributions, which makes the score's freshness state directly auditable.

Composition with cross-system coordination produces structurally consistent staleness handling. Multi-vendor mesh deployments — different vendors' systems consuming observations from a shared authority — apply identical TTL logic because the TTL is a property of the observation rather than of the consuming system's interpretation. An observation that authority A signs with TTL X is treated identically by all consumers that hold A's credential, regardless of which vendor's stack the consumer runs. Cross-jurisdictional operations gain the same consistency: when a vehicle moves between authority domains, observations from each authority carry their own TTLs, and the receiving system applies the originator's TTL with consistency that does not depend on the vehicle being an in-domain or out-of-domain device.

Prior-Art Context

Time-to-live as a wire-format field is well-established — IP packet TTL (RFC 791), DNS record TTL (RFC 1034), HTTP cache TTL (RFC 7234), countless application-layer caches. None of this prior art binds the TTL cryptographically to the originating authority's credential, enforces a class-bounded maximum, or treats expired contributions as structurally zero in a downstream decision pipeline. The prior art treats TTL as a hint about cache freshness; the disclosed mechanism treats it as a credentialed declaration of validity that gates decision-grade admissibility.

Per-system staleness handling in capability and situational-awareness systems is the dominant prior art. Each system implements its own freshness logic, often by inferring staleness from observation timestamps against system-internal policy. The pattern produces inconsistency: different systems admit the same observation with different staleness assumptions, leading to coordination failures when the systems must agree about whether the observation is current. Cross-system coordination requires consistent staleness handling, which the per-system pattern cannot produce because each system's policy is internal and unaudited.

Cryptographic short-lived tokens (OAuth access tokens, JWT exp claims, Kerberos tickets) carry expiration metadata signed by an issuer, which approaches the disclosed mechanism in form. They do not, however, integrate with a downstream multi-input decision evaluator in which expired contributions structurally zero out, nor do they impose class-bounded maxima at the schema layer, nor do they require evaluation-time audit recording. The disclosed mechanism advances the prior art by integrating credentialed expiration with decision-pipeline structure and audit obligation.

Disclosure Scope

The Cognition Patent discloses observation TTL governance as a primitive of the capability-awareness layer. The disclosure includes (a) the cryptographic binding of TTL to observation payload and authoring credential at the originator; (b) the class-bounded maximum TTL enforced through governance-published class schemas; (c) the structural-zero contribution of expired observations at the capability evaluator; (d) the mandatory audit recording of TTL state at every evaluation; (e) the layering of consumer-side staleness restriction over originator-declared TTL with the originator's value as upper bound; and (f) the alternative embodiments covering soft expiration, re-attestation, distributed-clock TTL semantics, and probabilistic-freshness reporting.

The disclosure scope contemplates application across V2X situational awareness, multi-domain defense capability scoring, cross-jurisdictional regulatory attestation, multi-vendor industrial control, and any other domain in which decision-grade evaluators consume observations from heterogeneous authorities and require cross-system consistency in freshness handling. The patent positions the primitive at the layer where observation-lifecycle management has historically operated without architectural support — where each system reinvents staleness logic and each multi-vendor integration encounters the consistency gap as a recurring engineering problem. By making freshness a credentialed, class-bounded, audit-recorded property of the observation itself, the architecture eliminates the gap at its source.