Carrara ( ; ; , ) is a town and comune in Tuscany, in central Italy, of the province of Massa and Carrara, and notable for the white or blue-grey marble quarried there. It is on the Carrione River, so
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 0x7842c8088d56b7b35fb3968335d2be48d1077751ea9c9bd72bf9cec201c11126. Chain 2 (Bitcoin): anchored in block 953648 (2026-06-14T15:20:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3e303174-3119-46f6-83d3-60fad72426d9.json and https://artists.proofprofile.net/proofs/artist/3e303174-3119-46f6-83d3-60fad72426d9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).