The Monk by the Sea () is an oil painting by the German Romantic artist Caspar David Friedrich. It was painted between 1808 and 1810 in Dresden and was first shown together with the painting The Abbey
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 0xd9cc770f452cf589a4866ba0c1dbb08d196d2808a2de353f1a06b280e9a4043d. Chain 2 (Bitcoin): anchored in block 953864 (2026-06-16T00:30:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0426319a-c2c6-4393-9ba8-a601fcf633cb.json and https://artists.proofprofile.net/proofs/artist/0426319a-c2c6-4393-9ba8-a601fcf633cb.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).