Trusted sensor ingress layer (TSIL): receipt-gated, fail-closed sensor ingress with signed-head freshness
Systems and methods for receipt-gated, fail-closed sensor ingress at the OS/HAL boundary. A portion of acquisition executes in a trusted boundary; each event is deterministically canonicalized into a Sensor Receipt (S2), signed, and its commitment anchored to an append-only log that publishes signed heads and supports inclusion and append-only-evolution (consistency) proofs under a freshness policy. An ingress gate admits the event to an OS read/subscribe path only after successful validation within an admission latency budget; otherwise the system returns a Structured Precondition-Failure code and withholds the event. Optional active liveness (optical flicker, IR, ultrasonic) and multi-sensor consistency detect replay and spoofing. On PASS, a scope-bound, TTL-limited, single-use sensor-permit may be minted to authorize read/subscribe. A verifier may emit a digitally signed Certification Result and, optionally, a Sensor Integrity Score. Zero-knowledge predicates may prove policy satisfaction without revealing raw sensor values. The rail yields portable, independently verifiable evidence of policy-compliant sensing.
1 . A computer-implemented system comprising one or more processors and memory storing instructions that, when executed, cause the system to operate as a sensor ingress rail, the system configured to:
(a) execute at least a portion of sensor acquisition within a trusted boundary;
(b) deterministically canonicalize a sensor event and compute a Sensor Receipt (S2) comprising at least a boundary measurement, an input digest, a monotonic counter, a trusted event time, and an anti-replay tuple;
(c) anchor a commitment of the S2 to an append-only log that publishes signed heads and supports inclusion and append-only-evolution (consistency) proofs under a freshness policy;
(d) validate inclusion under the freshness policy and, responsive to a head change observed within a freshness policy window, validate an append-only-evolution (consistency) proof; and
(e) via an ingress gate, admit the sensor event to an operating-system (OS) read/subscribe path only after the successful validation, and otherwise, by the ingress gate, return a Structured Precondition-Failure (code) and withhold the event such that no read/subscribe consumer or DMA client can observe the event before admission.
2 . The system of claim 1 , deployed on a device comprising a sensor interface and an ingress gate coupled to an OS sensor bus, the system further configured to:
(a) enforce fail-closed admission within a latency budget;
(b) perform at least one active liveness challenge for a modality selected from the group consisting of camera, microphone, and RF, and the system denies admission upon mismatch; and
(c) emit signed evidence of allow-or-deny decisions including timing measurements.
3 . The system of claim 1 , further comprising executable instructions that, when executed by the one or more processors, cause the system to: (a) validate S2 proofs and multi-sensor consistency graphs across at least two modalities selected from the group consisting of GPS, IMU, barometer, and camera; and (b) emit a digitally signed Certification Result committing to a receipt identifier, at least one head identifier, and a verifier identity.
4 . The system of claim 1 , further comprising a privacy component configured to accept zero-knowledge predicates proving satisfaction of a policy constraint for a sensor event without revealing raw sensor data, wherein failing or missing proofs map to a Structured Precondition-Failure (code) selected from the group consisting of PRIVACY_PROOF_REQUIRED and PRIVACY_PROOF_FAIL.
5 . The system of claim 1 , wherein the anti-replay tuple comprises at least one item selected from the group consisting of a nonce, a policy epoch identifier, and a profile identifier.
6 . The system of claim 1 , wherein the freshness policy enforces a maximum-merge-delay window, and validation failure maps to STALE_HEAD.
7 . The system of claim 1 , further configured to perform at least one active liveness challenge for a modality selected from the group consisting of camera, microphone, and RF, the challenge comprising at least one of an optical flicker, an infrared pattern, or an ultrasonic watermark, wherein a mismatch maps to SPOOF_DETECTED.
8 . The system of claim 1 , further comprising a consistency graph that encodes velocity or altitude bounds across modalities, wherein a contradiction maps to CONSISTENCY_FAIL.
9 . The system of claim 1 , wherein admission includes minting a sensor-permit that is scope-bound, time-to-live limited, and single-use, and rebinding attempts map to PERMIT_REPLAY.
10 . The system of claim 1 , wherein the ingress gate supports a Short-Permit (HOLD) with reduced resolution or rate until quorum or continuity is completed.
11 . The system of claim 1 , wherein denial returns a Structured Precondition-Failure (code) selected from the group consisting of POLICY_DENIED, PROOF_REQUIRED, and TIME_BUDGET_EXCEEDED.
12 . The system of claim 1 , wherein a local signed-head cache and proof prefetch are maintained with a time-to-live configured to satisfy the latency budget.
13 . The system of claim 1 , wherein the privacy component validates zero-knowledge predicates comprising set-membership or range proofs.
14 . The system of claim 1 , wherein recording or forwarding APIs enforce the sensor-permit at egress, and re-broadcast without a valid permit is denied.
15 . The system of claim 1 , wherein radio-frequency (RF)/global navigation satellite system (GNSS) path proofs selected from the group consisting of time-of-flight and multi-tower triangulation are included in an S2 extension.
16 . The system of claim 1 , wherein the Certification Result includes a profile identifier, a status, at least one code, head identifiers, a verifier identity, and an issuance timestamp.
17 . The system of claim 1 , wherein, upon admission, the system returns allow-or-deny evidence signed within the trusted boundary and anchored to the append-only log, and wherein the system is further configured to package the allow-or-deny evidence into an EvidenceBundle and to (i) include in the EvidenceBundle one or more cross-rail references to external governance receipts emitted by one or more external safety rails selected from the group consisting of a trusted reality compositor rail, a clinical safety rail, and a multi-harm Safety Risk Budget Engine, and (ii) treat the cross-rail references as evidentiary-only links that do not alter fail-closed admission predicates enforced by the ingress gate.
18 . The system of claim 1 , wherein the read/subscribe path includes at least one of:
(i) an operating system/hardware abstraction layer (OS/HAL) bus submit or commit;
(ii) a firmware/real-time operating system (RTOS) driver commit;
(iii) an accelerator direct memory access (DMA) queue or fence;
(iv) a virtualization shim;
(v) a network offload device, including a smart network interface card (SmartNIC) or a data processing unit (DPU);
(vi) an image signal processor (ISP)/encoder pipeline;
(vii) a field-programmable gate array (FPGA)/application-specific integrated circuit (ASIC) bridge; or
(viii) a gateway/proxy bridge;
and wherein gating occurs before subscriber visibility.
19 . The system of claim 1 , wherein a verifier timeout is treated as a Structured Precondition-Failure (code) with TIME_BUDGET_EXCEEDED and the event is dropped within the admission latency budget.
20 . The system of claim 1 , wherein under a snapshot-freshness policy a validator accepts a monotonic snapshot identifier (snapshot_id) issued by a transparency service and validates monotonic advancement within a policy window as an alternative to an append-only-evolution (consistency) proof.
21 . The system of claim 1 , wherein the ingress gate enforces a status-stapling recency bound for at least one of: (i) a vector of head commitments; and (ii) a sensor-permit status; and staleness maps to STALE_HEAD.
22 . The system of claim 1 , wherein admission further requires a valid CalibrationCertificate for the sensor and denial maps to CALIBRATION_EXPIRED.
23 . The system of claim 1 , wherein k-of-m validators are required for acceptance and quorum disagreement maps to HOLD with a signed conflict record.
24 . The system of claim 1 , wherein continuity records link successive signed heads observed during validation.
25 . The system of claim 1 , wherein the S2 includes a trusted event time derived from a trusted clock comprising a trusted execution environment (TEE) monotonic counter combined with attested network time.
26 . The system of claim 1 , further configured to validate a plurality of S2 streams and emit a digitally signed batch attestation that enumerates, for each stream, head identifier(s) and proof reference(s).
27 . The system of claim 1 , wherein upon reaching a policy-defined threshold of Structured Precondition-Failures for a sensor or device within a policy window, the ingress gate enters a quarantine mode that isolates the sensor interface, emits a signed continuity record, and restricts admission to a Short-Permit (HOLD) profile until remediation is observed.
28 . The system of claim 1 , wherein admitting the sensor event further requires receipt of a digitally signed Certification Result that commits to the S2 receipt, the head identifier(s), and a verifier identity.
29 . A computer-implemented method comprising:
(a) executing at least a portion of sensor acquisition within a trusted boundary;
(b) deterministically canonicalizing a sensor event and computing a Sensor Receipt (S2) having at least a boundary measurement, an input digest, a monotonic counter, a trusted event time, and an anti-replay tuple;
(c) anchoring a commitment of the S2 to an append-only log that publishes signed heads and supports inclusion and append-only-evolution (consistency) proofs under a freshness policy;
(d) validating inclusion under the freshness policy and, responsive to a head change within the freshness policy, validating an append-only-evolution (consistency) proof; and
(e) admitting the sensor event to an OS read/subscribe path only after successful validation, otherwise returning a Structured Precondition-Failure (code) and withholding the event.
30 . A non-transitory computer-readable medium storing instructions that, when executed, cause one or more processors to perform operations comprising:
(a) executing at least a portion of sensor acquisition within a trusted boundary;
(b) deterministically canonicalizing a sensor event and computing a Sensor Receipt (S2) having at least a boundary measurement, an input digest, a monotonic counter, a trusted event time, and an anti-replay tuple;
(c) anchoring a commitment of the S2 to an append-only log that publishes signed heads and supports inclusion and append-only-evolution (consistency) proofs under a freshness policy;
(d) validating inclusion under the freshness policy and, responsive to a head change within the freshness policy, validating an append-only-evolution (consistency) proof; and
(e) admitting the sensor event to an operating-system (OS) read/subscribe path only after successful validation, otherwise returning a Structured Precondition-Failure (code) and withholding the event.