thumb|right|upright=1.35|Barbershop quartets, such as this US Navy Band ensemble, sing four-part pieces, made up of a melody line (normally the lead) and three harmony parts. In music, harmony is the
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 0x0740da5dd725087df6c01ab37a102114d805b8e6d6c6730a15a738b410886bcd. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/97e32bad-85d1-44a5-89d1-e610432e8a04.json and https://artists.proofprofile.net/proofs/artist/97e32bad-85d1-44a5-89d1-e610432e8a04.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 0xf82ff68ccd09f53ec8d2cacd89fa9cb380849da2182849ce2a2118d3580c383c. Chain 2 (Bitcoin): anchored in block 957644 (2026-07-12T03:18:52Z), 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/USDHM0805427.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3aa617f59c31608998615f5c80ead085fb99e4fbedcd8c88f8656b7d00f7f3f9. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/USDHM0805428.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x53b9527d2bd05397267283f45b3f3fdab3ee2c248f4e019bd56badd4dd303f68. Chain 2 (Bitcoin): anchored in block 958543 (2026-07-18T11:58:44Z), 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/USDHM0805429.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c8296379185fb59c99b45fb7d98b4275d46f11d93e930fa39bec1308dc16ca1. Chain 2 (Bitcoin): anchored in block 958796 (2026-07-20T02:53:03Z), 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/USDHM0805430.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2d6aa7359f34799df8272532df11564e9872336d8f42b03478ccf4221d9e558b. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/USDHM0805431.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x264adba13815ac019b4fe38ccea18022f00476ccfd0dadd5f388c499e7c275b9. Chain 2 (Bitcoin): anchored in block 958601 (2026-07-18T19:27:02Z), 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/USDHM0805433.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcee04df93cd5caacfa4ac15eee731cadde9de193a7aec1f24c393f015aa2ac73. Chain 2 (Bitcoin): anchored in block 956728 (2026-07-05T01:43:49Z), 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/USDHM0805434.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe48efff999830bf078521e9539b72b1db13c6813a095d187d8846f52cd9bba29. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/TCACB1460746.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0e77b00c71aa2d504ee08bbfe3545b6f58dea6854338eb41b3db66b8d0011f1. Chain 2 (Bitcoin): anchored in block 957741 (2026-07-12T18:30:59Z), 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/TCACB1460752.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcc62f416f3bce312459eab44c1f39d699f2d8caafc583f0782cfb8dd7522e9a6. Chain 2 (Bitcoin): anchored in block 958547 (2026-07-18T12:44:05Z), 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/TCACB1460753.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x922ff78fb7f6132ceaceecebcec06bcf9f5dbc5b89716dd4a0ae017b0d1e5e7b. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/TCACB1460755.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1b5b5c75ff506273d058515863c0105b08a141a0a6b8a685b6b684e773b7748f. Chain 2 (Bitcoin): anchored in block 958690 (2026-07-19T07:14:39Z), 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/TCACB1460757.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa83e44a4550cda08529f827e729e57ba2a4a3500e3b4de5e2d21eea88c920b44. Chain 2 (Bitcoin): anchored in block 958251 (2026-07-16T06:29:25Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/TCACF1554358.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x24bb317245c90802b752f47a8e0d8e2bebd6493e16c9cfec516349efc190762e. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/TCACF1554359.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd35fe478d298ec9ab32acf7b9fd170e937934a3d1e8c13cddbbde161bc93a6cb. Chain 2 (Bitcoin): anchored in block 958251 (2026-07-16T06:29:25Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/TCACF1554360.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaaf4f1d99bb1ce71b877551301b000ef1f32b166553d41c23317e03bf0657b47. Chain 2 (Bitcoin): anchored in block 957728 (2026-07-12T16:20:40Z), 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/TCACF1554362.