Largo may refer to: Music Largo (Italian for 'wide', 'broad'), a very slow tempo, or a musical piece or movement in such a tempo "Largo" from Xerxes arranged from "Ombra mai fu", the opening aria f
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 0xd37b6e1d0c936aaf8ee88f5ffbeb53654356a497d81b0752de4591cf8a503c2f. Chain 2 (Bitcoin): anchored in block 953997 (2026-06-16T20:07:57Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2083a0d0-723d-48a5-934b-538e4a288687.json and https://artists.proofprofile.net/proofs/artist/2083a0d0-723d-48a5-934b-538e4a288687.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).