Twenty-one, XXI or 21 may refer to: 21 (number), the natural number following 20 and preceding 22 One of the years 21 BC, AD 21, 1921, 2021 Films The 21, directed by Tod Polson 21 (2008 film), sta
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 0xf041e35419ec4f1e0ebb8558331c624def9776ffad269ef7b8fcea8d41c44606. Chain 2 (Bitcoin): anchored in block 953907 (2026-06-16T07:39:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/15b81dc3-401c-44a6-9828-820a72fd457d.json and https://artists.proofprofile.net/proofs/artist/15b81dc3-401c-44a6-9828-820a72fd457d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
オン・ザ・ユニヴァーシティ・ストリート