thumb|250px|Montmartre seen from Notre Dame de Paris, including the Basilica of the Sacré-Cœur thumb|250px|A Garden in Montmartre by Pierre-Auguste Renoir (1880s) Montmartre ( , , ) is a large hill
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 0x68d01c95f9932e8bc005da08f50192b55a1c23f1a14e229e3d4fbce3bed9dbbf. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e50361d3-2396-4999-b7e0-afcf18fba940.json and https://artists.proofprofile.net/proofs/artist/e50361d3-2396-4999-b7e0-afcf18fba940.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 0x67008ffa7af4d2e8f2f35b7c6d670b09327e9089453a7bce25b8b78bd7223cff. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FXQ892300172.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x075e809d2b2014bb3303cb48faf71ec9be27ffc72404c93dec79112f5bc35d61. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/FR9W12435660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x075e809d2b2014bb3303cb48faf71ec9be27ffc72404c93dec79112f5bc35d61. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/FR9W12435660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x50417a360d6fac2849da05197efd2cf8a78761c830049a114b3c5676b739c5ab. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/FR9W12349113.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc3b0cc527e274a3db485d7fb09fcdaf23d1fb169d5485c44caebb100a4a42dc2. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/FR9W12231516.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7e7fc8a6e5886cedecf37a6ce40cfdb8761f0394f1c6e57542f2bfa2c2e37388. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/FR9W12419035.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf159ff53785c131c952aceec1eed5164343f70cc6dfddab4c1f3c8e15e033935. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/FRU702100245.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ef390128648cea9dfb18dd45a7c0ac6533aedd0c1608a1cae43d7f142c9bea6. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/FR9W12435658.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x143fceb8e64878b4a204cb55db31321d9a803445d13861ccec0dcab2ff39cef1. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/FR9W12435659.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe6583e18a7cf24fefcae93554af99bb2df86348dc2c094e3834265439cfc1367. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/FR9W12435661.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ef390128648cea9dfb18dd45a7c0ac6533aedd0c1608a1cae43d7f142c9bea6. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FR9W12435658.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x075e809d2b2014bb3303cb48faf71ec9be27ffc72404c93dec79112f5bc35d61. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/FR9W12435660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x143fceb8e64878b4a204cb55db31321d9a803445d13861ccec0dcab2ff39cef1. Chain 2 (Bitcoin): anchored in block 960160 (2026-07-29T22:48:59Z), 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/FR9W12435659.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20fb63d78b1dfb0b684a9557df878d5cbe0547d6e0cf3480b1bb642fa0bb6c8d. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/FRX852306300.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20fb63d78b1dfb0b684a9557df878d5cbe0547d6e0cf3480b1bb642fa0bb6c8d. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRX852306300.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x22325f4e8463680e78b5e6f3675b46a7f56e36b2fb77e9cd345fa23df4f45185. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/TCAIK2460645.