U1, U.I or U-1 may refer to: People and characters Yuvan Shankar Raja (stage name: U1; born 1979), a Tamil musician and film composer U-1, a fictional character, the protagonist of the Gitaroo Man vi
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 0x21777d1a1571d79ed9b5ce5d1b4d6aa8e9bd0cc9ade9b288fdcbad09c4488065. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ca2fc656-a7c3-445b-b0be-7786d0f56aba.json and https://artists.proofprofile.net/proofs/artist/ca2fc656-a7c3-445b-b0be-7786d0f56aba.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).