Proof Portal

Three things you can do here

1. Verify a supported card — supply the exact card and inspect its signature result rather than assuming it is signed.
2. Inspect the root — the current root lists 154 leaf digests. The separate 335-card index is a different corpus with zero identifier overlap.
3. Check inclusion — require the claimed index to point to the card’s exact digest before accepting its Merkle path.

Current exact-root state

The root shipped with this page has SHA-256 9b426735bc7c0e94d32ce64ccd87605880c531350ca957ecccde5046bde505cd, 154 leaves, and Merkle root 2fe2a76f310ea79268c73a94543c91125fa7acc3bbf11ed489afdfeb845ea745. Its Ed25519 signature verifies under did:web:csoai.org#board-attestation-1. This does not bind every card or every measurement.

1. Sigstore Rekor — exact preimage witnessed at log index 2714574265; receipt: rekor-root-9b426735.json.
2. OpenTimestamps — STAMPED_PENDING_BITCOIN. Proof SHA-256: 91dae23c5e4d8c4914fbfca77e8274e1ddfd71b00baadd8f58e43f3633bdfc99. It contains no Bitcoin block confirmation.
3. Scope — the OTS proof covers the exact root.json bytes only, not the separate signed-card index or an entire measurement history.
4. Machine-readable state — root-witness-latest.json.