Quorum-Based Identity Recovery: Peer Attestation After Memory Loss

Mechanism

Recovery begins with a recovery-request record signed by the operator using whatever residual signing capability remains—commonly a fresh, locally derived ephemeral key with no prior reputation. The request commits to the operator's biological signal as captured at the moment of request, the last chain head the operator can recall or recover from external archives, and the set of peers from whom attestations will be sought. The request is broadcast to those peers through any available channel; the channel itself is not trusted.

Each peer that receives the request evaluates it against its own local memory of prior interactions with the lost identity. The peer compares the asserted last-known chain head against its own record, examines the freshly captured biological signal against any previously cached liveness reference for that operator, and applies its own policy regarding what kinds of recoveries it is willing to attest to. A peer that elects to attest issues an attestation record committing to the request, the peer's own current chain head, the peer's local confidence score, and the peer's signature.

Attestations accumulate at the recovering operator. Once the number of received attestations meets the quorum threshold defined by the system policy, and once the aggregate confidence and the diversity of the attesting peers satisfy the policy's structural requirements, the operator constructs a recovery token. The token aggregates the attestations through a threshold-signature scheme or a Merkle-aggregated signature, and it commits to the recovery parameters that will govern the resumed identity: the initial trust slope, the action scope, the rate-limit applicable to subsequent operations, and the duration of the probationary window.

The recovery token is then bound into the trust graph by inclusion in a recovery-anchor record. The anchor record is propagated to relying parties through the same gossip and ledger mechanisms that propagate ordinary chain extensions. From the anchor forward, the recovered identity extends a new chain whose lineage is explicitly attributed to the recovery event. Operations performed under the recovered identity carry a recovery flag for the duration of the probationary window, signaling to relying parties that elevated audit and reduced scope apply.

Operating Parameters

The quorum threshold is the minimum number of attestations that must be received before a recovery token may be constructed. The threshold is set by system policy and is bounded below by a minimum that ensures no single peer or small collusion can produce a recovery. Embodiments express the threshold as a fixed integer, as a fraction of the operator's trust-graph neighborhood, or as a function of the trust slope held by the lost identity at its last known head.

The diversity requirement constrains the structural relationships among attesting peers. A naive quorum of peers all controlled by the same principal, or all hosted on the same substrate, would not satisfy the diversity requirement. Diversity is computed against the trust graph and against the substrate-attestation records that accompany each peer's chain head. The system policy specifies a minimum diversity score below which a quorum is rejected even if the count threshold is met.

The rate-limit parameter bounds how frequently a given identity may undergo recovery. A first recovery is permitted on the cooldown specified by base policy; a second recovery within the cooldown window is rejected outright; a third within an extended window triggers escalation to a stricter recovery procedure with higher quorum and lower initial slope. Rate limits are committed in the recovery-anchor record and are enforced structurally by the chain validator.

The initial-slope parameter specifies the trust slope at which the recovered identity begins extending its new chain. The initial slope is strictly less than the slope held at last known head; representative embodiments set it at a fixed fraction, at a value derived from the average confidence score of the attesting peers, or at a floor specified by relying-party policy. The slope ramps back toward its prior value through normal chain extension, subject to the trust-slope validator.

The probationary-window parameter specifies the duration during which the recovered identity is flagged. Within the window, action scope is restricted, audit obligations are elevated, and certain operations—such as serving as an attesting peer for someone else's recovery—are forbidden. The window may be expressed in elapsed time, in number of successful chain extensions, or in both.

The biological-continuity threshold specifies how closely the freshly captured biological signal must match the cached liveness reference held by attesting peers. The threshold is calibrated to admit ordinary biometric drift while excluding substitution attacks. Peers whose cached references are stale beyond a configured age decline to attest.

Alternative Embodiments

Several embodiments of the recovery mechanism are contemplated. In a first embodiment, attestations are aggregated through a BLS threshold signature, producing a single compact recovery token whose verification cost is independent of the quorum size. In a second embodiment, attestations are aggregated through a Merkle tree, producing a token whose verification cost is logarithmic in the quorum size but whose size scales with the number of attesters. In a third embodiment, attestations are aggregated through a zero-knowledge proof that the requisite quorum and diversity conditions are satisfied without revealing the identities of individual attesters.

The peer-selection procedure may be operator-driven, policy-driven, or hybrid. Operator-driven embodiments allow the recovering operator to nominate the peers from whom attestations will be sought; policy-driven embodiments require attestations from a deterministic subset of peers identified by structural position in the trust graph; hybrid embodiments require both an operator-nominated set and a policy-mandated set, each of which must independently satisfy the threshold.

The biological-continuity check may be performed locally by each peer, by a designated continuity oracle trusted by the system, or by a multi-party computation that aggregates partial liveness scores without exposing the underlying biometric data. Each variant trades off privacy, latency, and trust assumptions.

Embodiments differ in the disposition of the lost identity's prior chain. In a continuation embodiment, the recovered identity adopts the prior chain head as its parent and extends from there, marked with a recovery transition. In a fork embodiment, the recovered identity begins a new chain rooted in the recovery anchor, with the prior chain explicitly retired. In a hybrid embodiment, both chains coexist for the duration of the probationary window, allowing relying parties to accept whichever lineage is more useful to their own audit posture.

The rate-limit may be implemented as a hard ceiling, as a soft penalty that increases the quorum threshold for repeated recoveries, or as an exponential cooldown whose period doubles after each invocation. The choice is governed by the threat model of the deploying environment.

Composition With Other Primitives

Quorum recovery composes with the PKI-fallback mechanism described in a companion disclosure. A fallback session that exhausts its duration bound without restoration of the biological signal escalates into a recovery procedure. The fallback-exit record in such cases is replaced by a recovery-anchor record, and the audit transcript of the fallback window is committed into the recovery token so that relying parties can trace continuity from the last validly extended chain head, through the bounded fallback, into the recovered identity.

Composition with the trust-slope validator is structural. The validator treats the recovery anchor as a discontinuity in the slope, with the new initial slope bounded below the old slope by an amount disclosed in the anchor record. Peers and relying parties evaluating the recovered identity apply slope-aware policies that may decline operations exceeding the slope-permitted action class.

Composition with sparse-checkpoint verification is direct. The recovery anchor is itself a checkpoint, and it is mandatory regardless of the cadence parameter governing ordinary checkpointing. Verifiers reconstructing identity continuity across a recovery event encounter the anchor as an explicit transition with all governing parameters present.

Composition with the trust graph is bidirectional: the recovery procedure both consumes the graph (using existing edges to identify quorum candidates) and updates it (the recovery anchor records the attestation set, and peers who participated record their attestations in their own chains). Subsequent graph operations can then take recovery participation into account when computing diversity and confidence scores.

Prior-Art Distinctions

Social-recovery wallets in the cryptocurrency literature use guardian sets to recover access to lost keys, but they recover access to a key, not continuity of a biologically anchored identity. The disclosed mechanism is concerned with attestation of biological continuity, with the consequent ability to reject attempts to recover an identity whose original operator is no longer present.

Shamir secret-sharing schemes split a secret across shares such that a quorum can reconstruct it, but reconstruction yields the original secret and does not produce a new, structurally distinguished identity. The disclosed mechanism does not reconstruct any prior secret. It produces a fresh anchor whose authority derives from the aggregated attestations and whose scope is explicitly reduced relative to the lost identity.

Account-recovery flows in conventional federated identity systems rely on out-of-band channels (email, SMS, security questions) whose security posture is not part of the identity system itself. The disclosed mechanism treats recovery as a first-class operation of the identity system, with all parameters committed and all attestations cryptographically bound.

Web-of-trust signing in classical PGP allows peers to vouch for the binding between a key and an identity, but it does not provide a structural mechanism for re-anchoring an identity whose key has been lost. The disclosed mechanism specifically addresses re-anchoring, with bounded slope, scope, and rate.

Disclosure Scope

The mechanism described in this article is disclosed in Provisional Application No. 64/050,895. The disclosure is intended to support claims directed to: (a) systems wherein a lost keyless identity is recovered through aggregated attestations from a quorum of previously trusted peers attesting to biological continuity; (b) the structural bounding of recovery through quorum-threshold, peer-diversity, rate-limit, initial-slope, probationary-window, and biological-continuity-threshold parameters committed in a recovery-anchor record; (c) the cryptographic aggregation of attestations through threshold-signature, Merkle, or zero-knowledge constructions; (d) the re-anchoring of the recovered identity at a trust slope and action scope strictly bounded below those held at last known head; and (e) the composition of the recovery procedure with bounded fallback states, sparse-checkpoint verification, and trust-graph maintenance.

Embodiments enumerated under "Alternative Embodiments" are intended as non-limiting examples. The scope of the disclosure extends to any combination, sub-combination, or substitution of equivalent mechanisms that achieves the structural property of bounded, rate-limited, biologically anchored recovery within a keyless identity system. Implementers are referred to the full provisional specification for claim language, drawings, and additional embodiments not enumerated here.