Tuna da Universidade Católica Portuguesa - Porto
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 0x1d852b04ad569ceb753c270985020b4f05c3bbee56c0f22ff2b1c57bb1c45081. Chain 2 (Bitcoin): anchored in block 953704 (2026-06-14T22:58:38Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/7a60c043-5a55-4900-948c-bf3f7802aaec.json and https://artists.proofprofile.net/proofs/artist/7a60c043-5a55-4900-948c-bf3f7802aaec.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 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 0x5c04b6223eb4f7a37745f7dba2abe61c78c2298846a51d0d4f9c5339ed323140. Chain 2 (Bitcoin): anchored in block 958563 (2026-07-18T14:29:03Z), 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/SE6A91825139.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb18eb6a15ee6c90f34e539fb492ddf1152212a374116a02e665afd977898bacf. Chain 2 (Bitcoin): anchored in block 956775 (2026-07-05T10:41:06Z), 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/SE6A91825158.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2f697c238f21c8cbbb7f66799cd5a90af6bd0207b6e4a4fff7cde9e08bb4440b. Chain 2 (Bitcoin): anchored in block 958480 (2026-07-18T02:58:58Z), 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/SE6A91838201.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44fd8b75cde18d22e78f02fa68c2907aa3781ba2d1af199fdb65073949a63ad2. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/SE5752489589.