Certified evidence for disputes comes from five different tool families. Notarisation and e-signature platforms (DocuSign, Adobe Acrobat Sign) certify document signing events. Forensic preservation and eDiscovery tools (Relativity, Nuix, Cellebrite) capture and hash artifacts after the fact. Timestamping authorities (DigiCert, Sectigo, and other RFC 3161 services) prove a digital object existed at a point in time. Software supply-chain attestation (Sigstore, in-toto) signs build and artifact provenance. Certified AI execution records prove what an AI system actually ran, which none of the other four capture. NexArt implements that last category: each execution is sealed into a Certified Execution Record with a canonical hash, an Ed25519 attestation, and an RFC 3161 timestamp, verifiable offline by any party.
Category map
These categories are complementary rather than competing. Most enterprise stacks need more than one of them, and the common mistake is assuming one category covers another.
| Category | Representative tools | What it covers | What it does not establish |
|---|---|---|---|
| E-signature and notarisation | DocuSign, Adobe Acrobat Sign, remote online notarisation providers | Who signed what document, when, with an audit trail of the signing ceremony | Concerns documents and consent events, not automated decisions or model behaviour. |
| Forensic preservation and eDiscovery | Relativity, Nuix, Cellebrite, hash-based evidence bags | Defensible collection, chain of custody, and hashing of data already in existence | Collects after the fact. If the original run left no reliable record, preservation cannot manufacture one. |
| Timestamping authorities | DigiCert, Sectigo, other RFC 3161 TSAs | Proof that a specific byte sequence existed at a specific time | A timestamp alone says nothing about what the data represents or which model produced it. |
| Supply-chain attestation | Sigstore, in-toto, SLSA provenance, transparency logs | Signed provenance for builds and artifacts, with public transparency logging | Concerns how software was built, not what a deployed model did at inference time. |
| Certified AI execution records | NexArt CERs and Project Bundles | Input, output, model, version, parameters, and optional identity binding, sealed at execution time and independently verifiable | Proves integrity and timing, not that a decision was correct or lawful. Cannot be created retroactively. |
Where NexArt fits
NexArt covers disputes about automated decisions and agent actions. At the moment of execution, the record is canonically serialised, hashed with SHA-256, signed by the NexArt attestation node using Ed25519, and timestamped through DigiCert's public RFC 3161 authority. Optional identity binding ties the record to a case, account, or subject reference, so the disputed decision can be located later. Multi-step flows assemble into a Project Bundle with a single Project Hash that preserves ordering across steps. The opposing party verifies at verify.nexart.io or offline against the published attestation key, without an account and without relying on your infrastructure.
What NexArt does not cover
NexArt makes no claim about admissibility or evidentiary weight in any jurisdiction: those depend on local rules, the contractual context, and the operator's own procedures. NexArt does not provide legal advice, chain-of-custody services for third-party data, or an opinion on whether a decision was correct, fair, or lawful.
Why replaying the prompt does not settle a dispute
Re-running an input against a model does not reproduce the earlier output. Model versions change, sampling is stochastic, and retrieved context differs. A record captured at execution time is the only artifact that describes the run in question.
Typical dispute triggers
- A customer challenges an adverse eligibility, pricing, or moderation decision.
- A counterparty disputes what an autonomous agent committed to on your behalf.
- A regulator asks a deployer to reconstruct a specific high-risk run.
- An internal investigation needs to establish what an agent did rather than what policy required.
Related questions
Is a certified execution record admissible in court?
Admissibility is decided by the forum, not by a vendor. What a CER provides is a record whose integrity and timing can be checked by the other side independently, which addresses the usual objection that the custodian could have altered it.
Can we prove what happened without disclosing the data?
Yes. Confidential execution stores inputs, outputs, and identity fields as keyed commitments. Integrity and timing verify without revealing content, and a specific value can be selectively revealed and checked against its commitment.
Can we certify a past execution once a dispute starts?
No. Certification happens at execution time, which is precisely what makes the record credible. This is why coverage decisions are made before an incident, not after.