thumb|A metal pea whistle thumb|A 3D-printable whistle A whistle is a musical instrument which produces sound from a stream of gas, most commonly air. The whistle makes a high-pitched, piercing, and
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 0x27ed9cb1a68d163c35c3a50e5bc114de21bb985675670bdfd6c2d7713e20c069. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a2a8ffb1-08f2-42c1-9b16-0c3d4b97ea30.json and https://artists.proofprofile.net/proofs/artist/a2a8ffb1-08f2-42c1-9b16-0c3d4b97ea30.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 0x7a3ceb26e5e4a105570d215de5f6efcaaca0cfb778f01442778128a77f2e5044. 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/US39N0400405.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x79d264cdb1223c236a6d86ab8decb172542d42f65f5ee842755f33244c5d78e2. 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/US39N0400406.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xadd8d2b46114b569ac609f60afd32b5376ba01990528a563c79772ebbe4eadc8. 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/US39N0400409.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x30a8374c847b91b78d723fa80c27201f2aae3c92cb407912a1cc54aab0873a74. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/US39N0400407.
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 0x955cf8c7e20f01a3b502635e72c4c30c3c2c4df569492599b087285eeafb3aa9. Chain 2 (Bitcoin): anchored in block 960296 (2026-07-30T19:11:09Z), 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/US39N0400408.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdda80eacc31d5be7bab882a8715f569e1e2594fb84725e3686eb7260d1a3e034. Chain 2 (Bitcoin): anchored in block 960291 (2026-07-30T18:23:33Z), 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/US39N0400410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2f75b664637b67680005c43b9f5a6937b74fcc4c309d92bbfcd858d5a201c153. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/US39N0400399.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbb138258714bee3d36f32218a76c207404d1cce2fb4528668365823b1b45594d. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/US39N0400400.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbbb654c11aa6962fb387c1a4176adb8b6414df12c7612140542510a8ca541465. 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/US39N0400404.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x018642acd4cd21ee584d8464c3e470a580411f952efdc836e994d7bd8dbb5931. Chain 2 (Bitcoin): anchored in block 960506 (2026-08-01T03:50:58Z), 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/US39N0400397.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x288a927a87f58190e5a94d5242109b6f5835d1b5211edae03f4958d1adbd9415. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), 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/US39N0400401.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb7b248331ad89936f747181b610cae757cc2e53e002766c5f097f7a6beb946fa. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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/US39N0400402.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3e64ec49b705c2ff42b4728ac2c445d941cb3540cee8d39701f620497fd6445d. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/US39N0400403.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3f2465668e998c736ca7a0d352cf6f6037dca83c85f560177dd8bc8d35d8f6fd. 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/SE5XG2346909.
Battle of the Remixers, Vol. 1: Just Buggin'
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x22c98cc6964476e95f7c34a9a706e49b615591f6e18494ce88e57e6484b2be4f. 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/GBBXG1120035.