Dynamic Device Hash Continuity Without CRLs or OCSP

Mechanism

The dynamic device hash continuity mechanism operates as a closed loop between three computational roles: the device itself, the credentialing authority that issued the device's initial hash, and the receiving peers in the governed mesh that consume the device's credentialed observations. At protocol initialization, the credentialing authority issues a root device hash bound to a hardware-rooted key material set held inside the device's secure element. The root hash is the only hash that is signed directly by the authority's long-term key; all subsequent hashes are produced by the device itself under the protocol's continuity rules, then countersigned by the authority within the active epoch's signing window.

Each epoch corresponds to a configurable rotation period whose duration is a parameter of the deployment. At the close of every epoch, the device generates a successor hash by applying a one-way function to the concatenation of the prior hash, a fresh nonce drawn from the secure element's hardware random source, and an epoch counter that increments monotonically. The device then constructs a continuity proof: a zero-knowledge demonstration that the successor hash is the canonical successor of the prior hash under the protocol's deterministic derivation function, without revealing the linkage in a form that an external observer can use to correlate epochs. The continuity proof is what permits the device to retain accumulated authority across rotations while denying long-term tracking surface to passive observers.

The credentialing authority countersigns the successor by examining the continuity proof, the device's current standing under the authority's policy, and any out-of-band telemetry that bears on whether the device should remain admitted. If the authority countersigns, the successor hash becomes the device's current hash for the subsequent epoch. If the authority withholds the countersignature, the device's chain terminates at the prior hash and the device falls out of admissibility at the moment the prior hash's validity window closes. There is no separate revocation list, no online status responder, no out-of-band notification: revocation is the structural absence of the next link.

Receiving peers verify continuity by walking the received hash chain backward through countersigned successors until they reach a credentialed root that the receiver has previously cached or can verify through its own chain to a shared trust anchor. The walk is bounded by the receiver's local cache horizon and by the protocol's chain-length parameter, so verification cost is constant regardless of how long the device has been operating. Each successor in the chain carries a validity window expressed as an epoch range, and the receiver rejects any chain whose terminal successor's window has closed without a further countersigned successor having been issued.

The continuity proof is what distinguishes this construction from naive hash-chain authentication. A naive chain would either expose the same hash across all epochs (defeating rotation) or replace the hash without binding it to prior authority (defeating accumulated standing). The continuity proof binds the rotation to the prior identity in a verifiable way that is opaque to anyone outside the trust circle of the credentialing authority, so that a device's authority history travels with it across rotations without becoming a tracking primitive.

Operating Parameters

Epoch duration is the principal tunable parameter. Short epochs (seconds to minutes) maximize unlinkability and minimize the window during which a compromised hash retains validity, at the cost of higher rotation overhead and tighter coupling to the credentialing authority's availability. Long epochs (hours to days) reduce overhead but extend the exposure window. V2X deployments in the disclosed embodiments adopt epoch durations on the order of minutes, balancing the tracking-resistance objectives of the SAE J2945 family against the operational reality that vehicles transit through coverage gaps. Defense and expeditionary deployments adopt shorter epochs in contested environments and longer epochs when operating fully disconnected, with the epoch counter advancing on a schedule pre-shared with the authority before disconnection.

Chain-length parameters bound the verification cost. The protocol caps the number of successors a receiver must walk before reaching a known-good anchor, with intermediate anchor publication ensuring that long-running devices do not produce unbounded chains. Anchor publication occurs at protocol-defined epoch multiples and is itself a credentialed observation that propagates through the mesh.

The continuity-proof construction is parameterized by the underlying zero-knowledge primitive. The disclosed embodiments contemplate succinct non-interactive arguments, Schnorr-style proofs of equal discrete logarithms, and lattice-based constructions for post-quantum operating environments. Each embodiment offers different tradeoffs in proof size, verification cost, and resistance to quantum cryptanalysis; the protocol does not bind the construction to a single primitive and instead specifies the proof's verification interface.

Validity windows for individual successor hashes default to the epoch duration but may be extended by the credentialing authority for devices operating in known disconnection environments. The extension is itself a countersigned observation and is bounded by the authority's policy. A device operating in a tunnel, an underground facility, or a contested-RF environment may carry a successor whose validity window extends across the expected disconnection period, with the device falling out of admissibility automatically if the window closes before reconnection.

Alternative Embodiments

In a first alternative embodiment, the credentialing authority is itself federated rather than singular. Multiple authorities cooperate on countersignature through a threshold signing scheme, so that revocation requires concurrence among a quorum of authorities rather than the unilateral action of one. This embodiment is suitable for cross-jurisdictional V2X deployments and for international defense mesh where no single authority would be acceptable to all participants.

In a second alternative embodiment, the device hash is rotated on event-driven rather than time-driven cadence. Events that trigger rotation include movement across administrative boundaries, role changes, threat-level escalation, and accumulation of a configurable observation count. Event-driven rotation is suitable for deployments where epochs do not map cleanly to operating reality, such as autonomous mobile robots that operate in distinct facility zones with different governance regimes.

In a third alternative embodiment, the continuity proof is augmented with a binding to environmental telemetry such as time-of-day, geolocation, or RF environment fingerprints. The augmentation makes the continuity proof verifiable not only as a successor of the prior hash but as a successor produced under conditions consistent with the device's expected operating context, raising the cost of credential cloning even when the secure element is compromised.

A fourth alternative embodiment embeds the continuity-proof verification directly in receiving devices' silicon, allowing high-rate verification (tens of thousands of chains per second) without software cryptographic stacks. This embodiment is targeted at roadside infrastructure that aggregates V2X observations from dense vehicle populations.

A fifth alternative embodiment supports delegated continuity, where a device temporarily acts as a relay credentialer for downstream devices that cannot reach the primary authority. The relay's countersignature is itself bounded by the relay's own current hash validity, producing a recursive structure in which delegation cannot outlast the delegator's authority.

Composition With Adjacent Primitives

Dynamic device hash continuity composes with the broader memory-native protocol primitives disclosed in the same provisional application. The successor hash serves as the device-identity field in credentialed observations, so that every observation a device emits is implicitly bound to the device's current standing without separate revocation checking on the receiver. When the chain terminates, all observations the device subsequently emits are uncredentialed and fall out of the mesh's admissibility evaluation automatically.

The mechanism composes with the keyless-identity family by providing the device-identity-thread that a biological identity attestation binds against. An operator's biological continuity attestation references the device's current hash, and the binding remains live across both the operator's continuity attestation rotation and the device's hash rotation because both rotations preserve continuity proofs.

The mechanism composes with adaptive indexing by serving as the lineage anchor for index mutations a device proposes. A mutation's lineage references the device's hash chain at the moment of proposal; when later mutations are evaluated against the lineage, the device's continued admissibility is verified through the same chain rather than through a separate audit pathway.

The mechanism composes with mesh-wide observation propagation: successor-hash issuance is itself a credentialed observation that propagates through the same flooding and gossip channels as substantive observations, eliminating any separate distribution infrastructure for credential updates.

Prior-Art Distinctions

The Security Credential Management System developed for V2X PKI deployments under IEEE 1609.2 attempts to mitigate the operational burden of CRL distribution through short-lived pseudonym certificates and butterfly key expansion. These mechanisms reduce the per-certificate revocation surface but retain the structural dependency on a centralized revocation authority and on receivers' ability to obtain current revocation state. Disconnection breaks SCMS in ways that the dynamic device hash continuity mechanism does not experience, because admissibility under continuity-based revocation is evaluated entirely from the chain a peer presents rather than from external state a receiver must obtain.

Hash-chain authentication schemes such as those derived from Lamport's one-time-password construction and from S/Key produce successive authenticators by repeated hashing, but they do not preserve accumulated authority across rotations and do not produce the continuity-proof binding that allows a device's standing to travel with it. They also expose the chain root once the chain is exhausted, requiring re-credentialing.

Forward-secure signature schemes such as those derived from Bellare and Miner produce time-evolving signing keys that limit the damage of key compromise, but they do not produce a rotating identifier and so do not address the long-term tracking surface that conventional certificates expose.

Onion-routing pseudonym mechanisms decouple identity from network position but do not bind to credentialed authority and do not support the structured revocation-by-non-issuance pattern. They also impose latency overhead incompatible with safety-of-life mesh applications.

The combination of per-epoch rotation, continuity-proof binding, and revocation-by-non-issuance is not present in any prior system known to the inventors. The combination is what permits simultaneously satisfying the tracking-resistance, accumulated-authority, and disconnected-operation requirements that no individual prior mechanism satisfies.

Disclosure Scope

Provisional Application 64/050,895 discloses dynamic device hash continuity as a foundational primitive of the memory-native protocol, with claim scope reaching to the per-epoch rotation, the continuity-proof construction, the revocation-by-non-issuance pattern, the federated and event-driven embodiments, and the compositions with adjacent keyless-identity, adaptive-indexing, and observation-propagation primitives. The disclosure encompasses both the protocol layer and the silicon-level verification embodiments, and it reaches to the threshold-signing federated authority configurations contemplated for cross-jurisdictional deployment.

Continuation practice will pursue claim scope on the continuity-proof construction independently of the rotation cadence, on the federated authority configurations independently of the underlying continuity-proof primitive, and on the silicon embodiments independently of the protocol-layer disclosures. The disclosure is intended to support a family of related applications addressing the V2X, defense mesh, critical-infrastructure mesh, and federated-identity deployment surfaces.