thumb|right|Two child sisters, the elder tending to the younger . thumb|The Game of Chess (1555) by Sofonisba Anguissola (It depicts her sisters Lucia (left), Minerva (right) and Europa (middle) Angui
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 0x24bce206233fd3f0c0cf3c76da11f24624b6cb7eb4a0e4924c6cb7b4980edb56. Chain 2 (Bitcoin): anchored in block 953879 (2026-06-16T02:57:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0937c8d7-4ef6-4e39-a981-3d2545e14c05.json and https://artists.proofprofile.net/proofs/artist/0937c8d7-4ef6-4e39-a981-3d2545e14c05.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 0xd0ada8a84e53366d7eaa83ab2e184b904ca0097c76405c6fca2ed5ad02c03533. Chain 2 (Bitcoin): anchored in block 958746 (2026-07-19T17:51:21Z), 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/QZDA42448097.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x291be47525182665819a3e18f55b404266083faf0396957bf7306edbde86c3b3. Chain 2 (Bitcoin): anchored in block 958736 (2026-07-19T16:00:44Z), 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/QZTAX2404106.