right|100px|thumb|Del operator,represented bythe nabla symbol Del, or nabla, is an operator used in mathematics (particularly in vector calculus) as a vector differential operator, usually represented
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 0x6cee0eef8511a2a366f87ed4271a296eec030a11e45c89ec035dd409f2428396. Chain 2 (Bitcoin): anchored in block 953687 (2026-06-14T20:19:15Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/69636c9e-d208-4030-8db4-3e9f1516ba1f.json and https://artists.proofprofile.net/proofs/artist/69636c9e-d208-4030-8db4-3e9f1516ba1f.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 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 0x8c6948a798c169b405856d73b7e5c19048d4a199c6ca35674617a236aa59ab4f. Chain 2 (Bitcoin): anchored in block 958808 (2026-07-20T02:49:15Z), 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/QM2PV1834154.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x36ea1c3b1e29f33be0b4a6c942e16553d1ddd07c0932671ea5452f804e7caae2. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/QM2PV1836039.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3628795dbc824756da310e3e100194058ce0175f4562fbd50c9c2c234a83f12e. Chain 2 (Bitcoin): anchored in block 956857 (2026-07-06T01:26:17Z), 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/QM2PV1835438.