Alexander Abreu Manresa (September 6, 1976) is a Cuban trumpet player, songwriter and singer. He leads the band Havana D'Primera. He was born in Cienfuegos on September 6, 1976. By the age of 20, he
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 0x29a1d5bca9d866bf7d439a591b58f40ca1aeea39b717fcefeef3f88f68068239. Chain 2 (Bitcoin): anchored in block 954705 (2026-06-21T13:42:37Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f0ae493a-a00e-48dc-af5a-bb6b994585b1.json and https://artists.proofprofile.net/proofs/artist/f0ae493a-a00e-48dc-af5a-bb6b994585b1.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.