Subsonic may refer to: Motion through a medium Any speed lower than the speed of sound within a sound-propagating medium Subsonic aircraft, a flying machine that flies at air speeds lower than 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 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 0x6c639e39c2f2eae29a5da79d458d4847cabb6d581f8d60ea29b8e6a4296be7ba. Chain 2 (Bitcoin): anchored in block 953674 (2026-06-14T19:07:16Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/5b598825-a1e9-4af4-b37f-0a07a79e3bf7.json and https://artists.proofprofile.net/proofs/artist/5b598825-a1e9-4af4-b37f-0a07a79e3bf7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).