Orfeão Universitário do Porto (OUP) ComM • ComIP is a Portuguese student Association linked to the University of Porto dedicated to choir singing and Portuguese culture (mainly folk music and dance, a
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 0x75ef9fed0e969d49fa262cf8e24468b7ac42a3848811aefdba2b68a286eacfd4. Chain 2 (Bitcoin): anchored in block 953807 (2026-06-15T16:39:18Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f48a29e0-d6aa-4b74-a0d6-7ebe86f80a1a.json and https://artists.proofprofile.net/proofs/artist/f48a29e0-d6aa-4b74-a0d6-7ebe86f80a1a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Orquestra de Tangos do Orfeão Universitário do Porto (EP I)
Orquestra de Tangos do Orfeão Universitário do Porto (EP II)
Tuna do Orfeão Universitário do Porto (EP I)
Tuna do Orfeão Universitário do Porto (EP II)
VII FITU - Festival Internacional de Tunas Universitárias Cidade do Porto
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 0x5e3e8d9cc871a92edbca6a6d32c5f54f642b504a29fa2efd52757072bd1d64ec. Chain 2 (Bitcoin): anchored in block 959011 (2026-07-21T16:20:15Z), 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/GBSMU4028802.