A cusper is a person born near the end of one generation or the beginning of another. While the precise birth years defining when generations start and end vary, people born in these circumstances ten
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 0xe63c68dc3e319e066c7eeb8ce0050ea88bc9394aa32fa904f7f9e512f9f476aa. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/91ca0c8b-707e-48e8-b0db-02cc1855a781.json and https://artists.proofprofile.net/proofs/artist/91ca0c8b-707e-48e8-b0db-02cc1855a781.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).