A valid signature supports a narrow provenance claim; the content still needs independent evaluation.
State the claim being verified
A signed AI output record can link particular content to a signing key and reveal whether the signed bytes have changed. That is useful evidence, but it does not establish that the output is correct or that the signer measured the world honestly. The connection between a key and an organisation also requires a trusted identity process. Cryptographic verification and factual verification answer different questions.
Consider a measurement example
Imagine an agent reports that a warehouse contains 120 boxes and signs a receipt containing that count. A verifier can check the signature while the warehouse actually contains 90 boxes because the input spreadsheet was outdated. Recording the receipt on a blockchain would preserve the claim's history, not correct the count. A useful review therefore asks where the measurement came from, when it was taken and who checked the source.
Make the evidence boundary explicit
A practical receipt might identify the task, input hashes, output hash, model version when available, execution time and signer. Each field needs a defined meaning. A timestamp supplied by the producer is different evidence from an independently observed publication time. Hashing a private input allows later integrity comparison, but does not make the input publicly inspectable or automatically anonymise predictable sensitive information. Decide what disclosure is necessary before publishing an immutable record.
Verify the verifier
Ask which signature scheme is used, how keys are associated with identities and how compromised or revoked credentials are handled. Then test a deliberately modified receipt to confirm that verification fails as expected. Keep the result narrowly worded: signature valid, expected signer matched, content unchanged. Do not silently promote that result into model accurate, authorised action or truthful measurement. A strong provenance system is most useful when it states both what its checks establish and what remains outside them.
Sources & context
Sources checked 7 October 2026. This is explanatory coverage, not personalised investment advice. Our corrections policy.
