Siga was a Berber, Phoenician and Roman port located near what is now Aïn Témouchent, Algeria. Under the Roman Empire, it was part of western Mauretania Caesariensis, bordering Mauretania Tingitana.
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 0x4c47093108219184f8454d737ac0da9b3d037a31b13f6673152937db990e0f76. Chain 2 (Bitcoin): anchored in block 954346 (2026-06-19T03:51:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9424edb4-a63c-4971-8be0-9f532ee1da26.json and https://artists.proofprofile.net/proofs/artist/9424edb4-a63c-4971-8be0-9f532ee1da26.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).