40 or forty commonly refers to: 40 (number), the natural number following 39 and preceding 41 one of the years 40 BC, AD 40, 1940, 2040 40 or forty may also refer to: Music 40 (record producer)
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 0x70d5eab745b0d0bc91cedb5e928ac1df69eac7b8092d723e572ef636502cbe3e. Chain 2 (Bitcoin): anchored in block 953786 (2026-06-15T12:56:12Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d7f7ab82-0542-405a-919d-8eb3cd6983da.json and https://artists.proofprofile.net/proofs/artist/d7f7ab82-0542-405a-919d-8eb3cd6983da.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).