thumb|Bust of Joop Doderer as Swiebertje in Oudewater, Netherlands Johan Heinrich (Joop) Doderer (28 August 1921 – 22 September 2005) was a Dutch actor, well known for his role as the tramp Swiebertj
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 0x775c23c2c964ec6a0274138897df070c0fb3699956b8702620ca5258bf268445. 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/61a40bfb-02c0-47cf-8de2-37c2b03785a7.json and https://artists.proofprofile.net/proofs/artist/61a40bfb-02c0-47cf-8de2-37c2b03785a7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).