Verify an attestation receipt

Paste a receipt (a sample is loaded) and press Verify. Nothing is uploaded — the content hash and chain are recomputed here, in your browser, against draft-smith-corobate-attestation-receipt-00 (public, with samples and this verifier, at github.com/stan266/corobate-spec). This is the "re-run it yourself, trusting no one" step. Try the Tamper button: change one character and watch it break.

New here? See a receipt built from real inputs, end to end — a battery Digital Product Passport, from the manufacturer's spec sheet to a sealed receipt you can rebuild and re-check months later. Open the 5-step walkthrough →

This page checks the receipt's contents and its chain of fingerprints. It does not check the timestamp's signature — if you have a technical team, they can do that with one command: openssl ts -verify -data head.bin -in head.tsr -CAfile ca.crt. What it does confirm: content reproduction, the hash chain, the confidence gate, the point-in-time horizon, and that the anchor covers the head.
What the anchor is today (updated 26 July 2026): a genuine RFC 3161 token issued by freeTSA.org, a public timestamp authority we do not control. The root certificate travels with the receipt for convenience — fetch the same root yourself from freetsa.org and compare, and the timestamp is verified against an authority that has nothing to do with us. That is what makes check 5 mean what it sounds like.
Patent pending — U.S. Patent Application No. 19/747,068. © 2026 Corobate LLC. "Corobate" is a proposed product name pending trademark clearance.