Sebastian Da Costa (born 1990 in Luanda, Angola), better known by his stage name Daco Junior, is a singer/songwriter, rapper and a record producer from Vaasa, Finland. Daco Junior debuted in December
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 0xc3244dc85bb4ae4a1f7d8a3d7fbd163b09e96d2a0ae6a3aa1bb144146db55755. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f1c37162-44bd-4a37-9b79-4552c942e22b.json and https://artists.proofprofile.net/proofs/artist/f1c37162-44bd-4a37-9b79-4552c942e22b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).