ARC Proof

Every record ARC keeps (production data, evidence files, carbon results, statements, certificates and claims) is linked into a hash chain: each link holds the SHA-256 hash of the record and of the link before it. Each day ARC publishes the hash of the last link written before midnight UTC. A published anchor never changes.

Keep a copy of an anchor: the date, the link number and the hash. Saving or printing this page is enough.

Later, recompute the chain up to that link, for example from the chain records in an evidence package or a chain verification report that Acriva or your verifier provides.

If the recomputed hash of that link equals the published hash, no record written up to that day was changed afterwards. If it differs, the records were changed: contact Acriva and your verifier.