Joan may refer to: People and fictional characters Joan (given name), including a list of women, men and fictional characters Joan of Arc (c. 1412–1431), patron saint of France Joan (surname) Jōan (
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 0x89c756fb185c083db98ee1df6160609c0a5e82cb04e96587df0f82f526affe4b. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/74438294-b698-476c-89e9-c67a0870df78.json and https://artists.proofprofile.net/proofs/artist/74438294-b698-476c-89e9-c67a0870df78.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).