thumb|Yellow Sisters in Vlašimi, 2013 The Yellow Sisters are a Czech female vocal quartet, known for singing a cappella. Its members are Antonia Tereza Nyass, Barbora Vaculíková, Lucie Hawa Goldin 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 0xe33a513d2d673976b5f8552fa9d872f1e23ef01d08329e85d092947262d45539. Chain 2 (Bitcoin): anchored in block 953694 (2026-06-14T21:38:09Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/714d1c8a-af39-489c-9e70-597c5006494e.json and https://artists.proofprofile.net/proofs/artist/714d1c8a-af39-489c-9e70-597c5006494e.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 0xa00418262edebde307a0c7e175976a91903525979d853eb67b2fe573ae4ff80d. Chain 2 (Bitcoin): anchored in block 956857 (2026-07-06T01:26:17Z), 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/CZA751251201.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2680f4e33d014e6a517f2f32468d5d24e08d201f0c6d2dc9bdb1eb4ab463ef4b. 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/CZA751251202.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3976447e1d798ecf23029fb818fc7eb8eca3f710cf270c2c51cb1a00542bb845. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/CZA751251203.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5d016358bad0ca459b4a142a42f651fd00dbf8715e72c95baecd06b5aa8e73ed. Chain 2 (Bitcoin): anchored in block 958935 (2026-07-20T22:08:19Z), 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/CZA751251205.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x53dfd008c95069b9b1396251c80ca175be6879d36c28e7faf8b22cb26b3b4334. Chain 2 (Bitcoin): anchored in block 956857 (2026-07-06T01:26:17Z), 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/CZA751251207.
Live & Petr Wajsar (Club Kino Černošice)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd513881acc4f7d00e9b624bd988cecfb2868999e9bcb8eaa18c85d0fc88ba093. Chain 2 (Bitcoin): anchored in block 958711 (2026-07-19T09:26:32Z), 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/CZA751758102.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6494c0966e7ba327971e7a34d9ea3f02e41b59f3d3dada9fa3be138d6570d0be. Chain 2 (Bitcoin): anchored in block 958793 (2026-07-20T01:34:11Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA751758103.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd1fd618cbad25cb16dcab0592fc045229fdd298db5f93577b47f7850f8afd894. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/CZA752570210.