Siena ( , ; traditionally spelled Sienna in English; ) is a city in Tuscany, in Central Italy, and the capital of the province of Siena. With a population of 52,991, it is the 12th-largest city in the
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 0x30a85081d3210b91bff50458d1df8bfa618380f102bfe622cf57102c8ceab31e. Chain 2 (Bitcoin): anchored in block 954623 (2026-06-20T23:40:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/caa645d3-e0f3-455a-8441-de487e815151.json and https://artists.proofprofile.net/proofs/artist/caa645d3-e0f3-455a-8441-de487e815151.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).