Logs tell you what someone claims happened. Replay-grade evidence lets anyone—regulator, insurer, auditor, opposing counsel—independently reconstruct the exact operational state and reach the same verification result. Without trusting you. Without trusting us.
Definition. Replay-grade evidence is the evidentiary standard that HATS records operational history to: a signed, deterministically re-executable governance chain. Unlike a log or audit trail, which describes an event, replay-grade evidence reproduces it — an independent verifier re-runs the frozen chain and reaches the byte-identical result. It is the evidence HATS records; it is not itself the runtime, the score, or the independent verdict.
The entire security industry is built on records that describe what happened. Descriptions can be altered, truncated, reinterpreted, or simply lost. None of the dominant paradigms produce independently reproducible evidence.
SIEM collects logs from multiple sources into one place. It does not verify that those logs are complete, unaltered, or internally consistent. Aggregated lies are still lies.
Observability platforms show you what your system is doing. They do not show you why it made a specific governance decision, or prove that it was the right one at that moment in time.
Audit trails list who did what. They do not capture the full operational state that led to that action. You can see the decision. You cannot reproduce it.
Append-only logs and Merkle trees can detect if something was removed. They cannot tell you whether the original entries were correct, complete, or governancally valid.
The question is not whether your logs were tampered with.
The question is whether your evidence can be independently reproduced.
Replay-grade is a specific evidentiary standard. Every operational decision becomes a cryptographic node in a deterministic governance chain. The chain is not a log. It is a reproducible computation.
Every operational decision—every policy evaluation, every access grant, every governance check—is recorded as a signed, timestamped cryptographic node. Not a text line in a file. A verifiable object.
Every node links to its predecessor through cryptographic chaining. The full governance lineage is preserved. You cannot insert, remove, or reorder nodes without breaking the chain.
The entire chain can be replayed from any starting point. Given the same inputs, any implementation will derive the same transcript, reach the same verification result, and produce byte-identical output.
Any third party can replay the chain using their own verifier implementation. No H33 software required. No API calls. No trust dependency. The protocol is the proof.
Every node is signed with post-quantum cryptography. The evidence survives the arrival of quantum computing. What you attest today remains verifiable in 2040, 2060, and beyond.
Verification rules are frozen at publication time. They never change retroactively. Evidence verified under version 1.0 remains verifiable under version 1.0 forever. No moving goalposts.
A log says "access was granted."
Replay-grade evidence says "here is the exact governance state, the exact policy version, the exact cryptographic chain—reproduce it yourself."
Replay-grade evidence is not a feature. It is an evidentiary standard that transforms how different stakeholders verify operational claims.
Do not ask the regulated entity to explain their compliance. Replay their governance chain. Reach the same conclusion independently. Or don't—and know exactly where they diverge.
Underwrite based on reproducible evidence, not self-reported questionnaires. Verify that governance controls were continuously active during the coverage period. Replay the chain at claims time.
Replace statistical sampling with complete deterministic verification. Replay every governance decision in the attestation window. Every node. Every chain link. Every policy evaluation.
Produce evidence that opposing counsel can independently verify. Post-quantum signed. Deterministically reproducible. Cryptographically chained. The chain either verifies or it does not.
When governance behavior is unexpected, replay the exact chain. See the exact policy version, the exact input state, the exact evaluation path. Reproduce the bug deterministically.
H33 is not another tool in the observability stack. It is infrastructure for a different category of evidence.
HATS is a publicly available technical conformance standard for continuous AI trustworthiness. Certification under HATS provides independently verifiable evidence that a system satisfies the standard's defined controls. No H33 dependency required. Any party can build a conformant verifier.
Security logs describe events; replay-grade evidence reproduces the decision — the same frozen evidence, replayed by an independent verifier, yields the same result. The proof is an artifact.
The replay-grade evidence linked below records a real, independent verification: a frozen evidence bundle produced by a different party was re-checked offline by an independent verifier, the decision matched, and the result was signed with an ML-DSA-65 verifier identity distinct from the bundle's producer.
What this does not claim: the verified bundle is a defined test fixture, not a production incident. What it demonstrates: the replay-grade evidence format and an independent verifier can reproduce a matching, cryptographically signed decision. The verifier is independent, the result is reproducible, and the subject is disclosed — the trust signal is that the system tells you what it is not claiming.
How Replay-Grade Evidence connects to the rest of the H33 system — its parts, its foundation, the standards and products around it, and the evidence that proves it.
When a claim about the past has real consequences — an insurance payout, a regulatory finding, a dispute — a description of what happened is not enough, because descriptions can be altered or contested. Replay-grade evidence exists so the past can be re-derived rather than merely asserted, by a party who trusts neither the producer nor H33.
An evidentiary standard in which every operational decision is a signed, timestamped cryptographic node chained to its predecessor, so the whole governance history can be deterministically re-executed and independently reproduced.
Decisions are recorded as post-quantum-signed nodes in a cryptographically chained transcript with frozen verification semantics. Any third party runs their own verifier over the frozen chain and, given the same inputs, derives byte-identical output and the same verdict — no H33 software or API required.
When a claim about the past carries real consequences — an insurance payout, a regulatory finding, a legal dispute — and an outside party must reproduce the decision themselves, now or years later, without trusting you.
It is not the runtime that produces the evidence (HATS records it), not the 74-byte portable primitive (H33-74 produces that), and not the independent verdict (Verification renders that). A matching replay proves reproducibility, not that the decision was wise.
Append-only logs and Merkle trees detect whether entries were removed or altered. Replay-grade evidence goes further: it lets a third party re-execute the decision and reach the same result — reproduction, not just tamper-detection.
Read the standard. Download the verifier. Or build your own. The protocol is the proof.