thumb|A tau cross (Saint Anthony's cross) The tau cross is a T-shaped cross, sometimes with all three ends of the cross expanded.Merriam-Webster: tau cross It is called a "tau cross" because it is sh
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabad99bd303d0c6e21b691281a309f309090626e859ab5483c7d0af2b191aa20. Chain 2 (Bitcoin): anchored in block 954549 (2026-06-20T10:56:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/aa1f2c2c-c730-4309-8e5c-b93e4cc95fa7.json and https://artists.proofprofile.net/proofs/artist/aa1f2c2c-c730-4309-8e5c-b93e4cc95fa7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).