A grook () is a form of short aphoristic poem or rhyming aphorism created by the Danish poet, designer, inventor, and scientist Piet Hein. He wrote over 7,000 of them from 1939 until his death in 1996
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 0x76e6504dd64474e0f00ecbae5648c09dbe4d5df9937ca86ed12a189cae4f8e8d. Chain 2 (Bitcoin): anchored in block 954553 (2026-06-20T11:51:30Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/abd8dd91-f395-4194-9161-772e0a47d362.json and https://artists.proofprofile.net/proofs/artist/abd8dd91-f395-4194-9161-772e0a47d362.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5b2a50da1eb599d7ba1abb1170236510c45f2ce0edc34df692f4a904e7ff8bb1. Chain 2 (Bitcoin): anchored in block 958547 (2026-07-18T12:44:05Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GB8KE2414169.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c2518056ac5612ab06d26f2370b26c0e93e1118ac9bcb0e8bc1248d20c1f67e. Chain 2 (Bitcoin): anchored in block 958711 (2026-07-19T09:26:32Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GB8KE2415188.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3379f2ccab87ef0487c6538396435f424d0464145d7bdf9ca22cab6d45ed5a93. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GB8KE2415598.