Delayed Slope Validation: Bounded Proof Windows for Disconnected Environments

Mechanism

Delayed validation is the disclosed means of authenticating a presentation after an interval of disconnection or latency by replaying successors from a stored checkpoint or anchor using a supplied slope proof. It addresses environments in which the continuity check a recipient would ordinarily perform at the moment of receipt is impracticable, because of latency, intermittent connectivity, or disconnection. Rather than abandoning verification or accepting the presentation provisionally, the mechanism carries enough material with the message for the recipient to reconstruct the missing portion of the sender's trust slope deterministically once it is able to.

In the memory-native substrate, identity is validated as progression along a trust slope: a sequence of successive dynamic identities, each a Dynamic Agent Hash (DAH) or Dynamic Device Hash (DDH) generated as a successor of a prior trusted value under an update rule that incorporates at least one unpredictability contribution and a volatile salt. Ordinary acceptance reconstructs the expected successor from the last trusted value and validates the presented value against it within policy-bounded continuity parameters. When intervening steps are missing because the recipient was disconnected, that single-step check cannot be performed directly, and the slope must be rebuilt across the gap before acceptance.

What the Sender Carries

A sender prepares a message bearing the sender's current dynamic identity and a transmission timestamp, together with a bounded set of mutation proofs that compactly represent the intervening trust-slope evolution since a previously trusted anchor. A slope proof is a bounded disclosure that includes per-step materials sufficient to deterministically recompute missing successors from a checkpoint or anchor, without exposing raw local state or static device secrets. These proofs enable downstream reconstruction without requiring continuous synchronization or external registries.

For each missing step in the transmission window, the per-step materials follow the same unpredictability sources used to form the slope. In the local-state embodiment, a step carries an extractor token derived from a stability-tuned local state vector with a per-step volatile salt. In the hardware-anchor embodiment, a step carries a keyed derivation computed from a static hardware anchor and a per-step volatile salt. In the hybrid embodiment, both contributions are included. The sender may also include an optional reference to the last periodic anchor or a checkpoint identifier to assist bounded replay.

Reconstruction by Replay

Upon receipt, a verifier that lacks a recent anchor replays the intervening steps by iteratively applying the update rule with the disclosed per-step materials, starting from its last trusted value and proceeding forward to the presented identity associated with the transmission timestamp. For each step, the verifier recomputes the successor from the immediately prior value and the disclosed token or tokens and salt. When local-state tokens are used, the verifier may evaluate a neighborhood constraint under local policy to bound drift across the reconstructed interval. When the chain opens to the referenced anchor or to the stored reference and the recomputed terminal value equals the presented value, validation succeeds and the presentation is accepted.

Because each successor depends only on the immediately prior dynamic identity and the disclosed per-step materials, the reconstruction is local and deterministic; delayed verification remains local and stateless once the checkpoint is obtained. No centralized authority, synchronized ledger, or external registry participates in the decision. Acceptance binds to a recomputed chain that opens correctly and terminates at the presented value, so deferring the check does not relax the continuity guarantee; it only moves the check to the point at which the materials needed for it are available.

Checkpoint Requests

If the verifier's stored state predates the referenced anchor, or if the supplied proof set is insufficient to complete the replay, the verifier issues a checkpoint request and receives a bounded checkpoint response comprising either a newer anchor reference or an additional short proof window, enabling the verifier to complete the reconstruction. A checkpoint, in this substrate, is a retained, trusted state, embedded in an agent or stored by a verifier, that allows reconstruction of missing successors using bounded proofs without retaining full history. Policy controls the checkpoint cadence, trading storage overhead against replay effort: more frequent checkpoints reduce reconstruction cost, while sparser checkpoints minimize storage at the expense of longer bounded proofs. As with the initial replay, the checkpoint exchange relies only on bounded disclosures and does not depend on external registries or synchronized ledgers.

Failure Conditions and Replay Resistance

Replay fails when a per-step token is inconsistent, a salt is stale relative to expected cadence, a neighborhood constraint is violated, or the recomputed terminal value does not match the presented value. In any such case the verifier rejects the presentation under policy. Optional actions include trust-score adjustment or quarantine pending subsequent corroboration from anchors or peers.

Delayed validation does not weaken replay resistance. Acceptance requires strict monotonic progression within the proof window and prevents replay by disallowing reuse of previously accepted successors for the same sender and context. A presentation whose recomputed successor regresses behind the verifier's stored reference, or that reproduces an already-accepted successor, is rejected on the same terms as a presentation validated synchronously.

Interaction With Two-Stage Authentication

Two-stage authentication screens a header-layer DAH for continuity prior to decryption, then validates an embedded sender DAH at the payload layer after decryption, with failure at either stage causing rejection. Delayed validation governs the header-layer reconstruction when intervening steps are missing. A related path handles the case where header-level continuity validation succeeds yet payload decryption fails due to recipient identity drift. In that case the recipient advertises its current anchor or checkpoint and the sender retries once using that anchor; failing that, the sender requests a bounded checkpoint response. Retries are limited by policy to a fixed attempt window to avoid oracle leakage while still enabling bootstrapping from sparse state.

Deployment

The delayed validation mechanism is agnostic to unpredictability source. In the hardware-anchor embodiment, the proofs convey keyed derivations that bind freshness to per-epoch salts. In the local-state embodiment, the proofs convey extractor tokens derived from stability-tuned local state vectors. In the hybrid embodiment, both are conveyed and concatenated in the update rule, and failure of either contribution is sufficient to reject the step. By allowing receivers to authenticate from sparse local state using bounded proof windows and optional checkpoints, the process enables secure operation in stateless, intermittently connected, or long-duration disconnected deployments, including delay-tolerant, mesh, opportunistic, or spaceborne links. It preserves the memory-resolved authentication model and avoids reliance on persistent credentials, centralized authorities, or synchronized ledgers.

Disclosure Scope

Delayed validation, comprising a sender message that bears a current dynamic identity, a transmission timestamp, and a bounded set of mutation proofs representing trust-slope evolution since a previously trusted anchor; the verifier's iterative replay of intervening steps under the update rule from its last trusted value to the presented identity using the disclosed per-step materials; the optional neighborhood constraint on local-state proofs; acceptance conditioned on the recomputed chain opening to the referenced anchor or stored reference and the terminal value matching the presentation; the checkpoint request and bounded checkpoint response when stored state predates the anchor or the proof set is insufficient; the enumerated replay-failure conditions with optional trust-score adjustment or quarantine; the requirement of strict monotonic progression with disallowance of successor reuse for the same sender and context; and the single-retry path when payload decryption fails on recipient drift, is disclosed in U.S. Application No. 19/388,580. This article describes that disclosed mechanism. The scope extends across the hardware-anchor, local-state, and hybrid unpredictability sources described therein, and is not limited to a particular hash, extractor, anchor cadence, or deployment substrate, provided that authentication proceeds by deterministic replay of the trust slope from a stored checkpoint or anchor using bounded slope proofs.