Samarra (, ) is a city in Iraq. It stands on the east bank of the Tigris in the Saladin Governorate, north of Baghdad. The modern city of Samarra was founded in 836 by the Abbasid caliph al-Mu'tas
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 0xcea7f84ad435283ed4c281d4f0a9d2ac2abab3fc7be2e678072376a697273642. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/5ccfe332-6855-4382-8a81-728128db56ce.json and https://artists.proofprofile.net/proofs/artist/5ccfe332-6855-4382-8a81-728128db56ce.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).