thumb|Piet Noordijk playing in Amsterdam, 2009 Piet Noordijk (May 25, 1932 – October 8, 2011) was a Dutch saxophonist. Noordijk played with orchestras and big bands, including The Skymasters, The Ram
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 0xa199231d0e14ee453f021771154e01d9e30dd9775fced74414b53933a7db47d4. 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/f14bcfd5-0b3d-4bf5-969f-3db61b25cff4.json and https://artists.proofprofile.net/proofs/artist/f14bcfd5-0b3d-4bf5-969f-3db61b25cff4.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 0xb73f92ec82e1fb0671e6fa5a6e09e164de917ada5438c3b5bdfb32d2e6022635. 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/GBHCD1710630.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf365730196d31633953e10d976b6d4cf7371124889f0d76fbef6f877a1b1353a. 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/GBHCD1710631.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4540054d97e1d6d3555b7d1f1194523dbac191fda4522824edcfbf34d94e019a. 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/GBHCD1710632.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3fc7cd1442a5c9b329e710c5c6a4812c3ca1ed5236d2d04a1f9209497889837f. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/GBHCD1710635.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8f707c1b6c2d659aed3f9a04ff55e80497d994414bfa78ab8f3e0d51215c84be. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/GBHCD1710638.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x41d85e6e72d7984a01cdc05ea5e83f12efbeb95636177f30dcdc51497c1554fa. Chain 2 (Bitcoin): anchored in block 960403 (2026-07-31T13:04:34Z), 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/GBHCD1710633.
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 0x8bb133b1e7f570b1abe3b4e05b45fcf298eaa5a967a3eaf940e41574ad0ce055. Chain 2 (Bitcoin): anchored in block 960403 (2026-07-31T13:04:34Z), 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/GBHCD1710634.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc4d9565ee2f7d86165b81913b7519737c2f998166f90a4b387661384c5423d53. Chain 2 (Bitcoin): anchored in block 960277 (2026-07-30T16:10:47Z), 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/GBHCD1710636.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7a311235dd2c85d15a8233b9acc3c7388e449b2544b5432213ddfb9478bd6eae. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), 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/GBHCD1710639.