This page signs a sample PLENA receipt with a real Ed25519 key generated in your browser, then runs the same client-side verifier the public site uses — checking the content hash, the digital signature, and revocation status. Change one character and the verification fails. Everything runs locally; nothing is sent to a server.
Status: Reference implementation · Client-side demo
One click generates an Ed25519 keypair, builds a sample refusal receipt, signs it, and verifies the signed result against the public half of the key. This demonstrates the cryptographic mechanism end to end.
After signing, change a single field in the signed receipt and re-verify. A valid signature only covers the exact bytes that were signed, so any edit is detected.