Cardboard Boxer is a 2016 American drama film written and directed by Knate Lee. The film stars Thomas Haden Church, Terrence Howard, Boyd Holbrook, Rhys Wakefield and David Henrie. The story is cent
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a1ee943c79f36bfe8b2e96ff61a0009f9e51cf58a0f872a2ef706052aaeb93b. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ed22cb86-9e47-44ec-9e6e-c938ed67fda1.json and https://artists.proofprofile.net/proofs/artist/ed22cb86-9e47-44ec-9e6e-c938ed67fda1.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.