right|thumb|Mass grave of 26 victims of the Spanish Civil War in 1936, excavated in 2014 A mass grave is a grave containing multiple human corpses, which may or may not be identified prior to burial.
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 0x210094f7ea5586b9cc01496942bdc90d708ff2be05bef38a06ed19ba035e51f2. Chain 2 (Bitcoin): anchored in block 953630 (2026-06-14T12:06:27Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/302ea870-720a-4072-b3e0-7018bdcb12d1.json and https://artists.proofprofile.net/proofs/artist/302ea870-720a-4072-b3e0-7018bdcb12d1.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
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 0x01196144254507a36a5d5b6887feb53afef300224ded35fcafe494e6616a25da. Chain 2 (Bitcoin): anchored in block 958931 (2026-07-20T21:15:01Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZB4J1811390 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5400c8751366c4a5a61cff74a2b597ce0056068f0d54c5e28eb4a77f517c91cc. Chain 2 (Bitcoin): anchored in block 958924 (2026-07-20T18:54:07Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZB4J1811391 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2547aa0246e45620e0cca39ba3082c6dae3131c32b5b0fec7b07b215424cbce2. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T12:33:25Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZB4J1811392 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x88d3b64eb888dd64f36500f79027592df8baa9d63da8f6a8e58e4eea031b91cc. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZB4J1811397 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc24749493f7b15e43915423fba2c00ea1030cecc197024cac53dae7d59ffef58. Chain 2 (Bitcoin): anchored in block 959100 (2026-07-22T05:29:55Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZB4J1856787 — a six-check JSON result.