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 0xae56cab5120e83ff2272b955af9264d8addfeb3d91b79282e783e87d180b6ac1. Chain 2 (Bitcoin): anchored in block 953605 (2026-06-14T07:39:50Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/117b67ba-aa2c-4b3b-848d-bb734fcff3b7.json and https://artists.proofprofile.net/proofs/artist/117b67ba-aa2c-4b3b-848d-bb734fcff3b7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
PONS Hörbuch Spanisch: La última fiesta de Cardeña [20 landestypische Hörgeschichten zum Spanischlernen (A2/B1)]
Kapitel 1.1 - PONS Hörbuch Spanisch: La última fiesta de Cardeña
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 0x2598e0275ac8bfd1df41ec42a5fedbca054080f4ab324f720132883a0e4682c7. Chain 2 (Bitcoin): anchored in block 956745 (2026-07-05T05:33:35Z), 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/DEWM51251198.
Kapitel 1.2 - PONS Hörbuch Spanisch: La última fiesta de Cardeña
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xac4398e0ae67681bd304cfb5dd14bf88045a46661ef58c0109907e626b7ed353. Chain 2 (Bitcoin): anchored in block 959009 (2026-07-21T13:14:47Z), 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/DEWM51251199.
Kapitel 2.3 & Kapitel 3.1 - PONS Hörbuch Spanisch: La última fiesta de Cardeña
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe841f30bb694063f8bfc661c048a40ff1cb84caf7ffbdc320346a5316f816c71. 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/DEWM51251203.
Kapitel 1.4 & Kapitel 2.1 - PONS Hörbuch Spanisch: La última fiesta de Cardeña
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf4bdd46136d78fd7513e4eafccbd4990bcaaae4495497054bc643f406fe07b85. 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/DEWM51251201.
Kapitel 1.3 - PONS Hörbuch Spanisch: La última fiesta de Cardeña
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf73da4fc0293a74e459a42b1ce0858144aa98d4da427266f637bd2be97b09006. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/DEWM51251200.
Kapitel 2.2 - PONS Hörbuch Spanisch: La última fiesta de Cardeña
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe22abea97b63aa01522da1b340ddc5cf461b7b2112cd80330a3891ea106a12e0. Chain 2 (Bitcoin): anchored in block 959114 (2026-07-22T08:41:42Z), 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/DEWM51251202.