Izquierdo (; Spanish for "left") is a Spanish surname. Notable people with the surname include: Adelaida Abarca Izquierdo (1923–?), Spanish Republican political activist Elisa Izquierdo (1989–1995),
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 0x6327460415d41efc09bd9f3096175c27713b5808990979127350d95b4819c03e. Chain 2 (Bitcoin): anchored in block 954618 (2026-06-20T23:05:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ca323840-98d7-43c7-8fac-d3a39f5793e8.json and https://artists.proofprofile.net/proofs/artist/ca323840-98d7-43c7-8fac-d3a39f5793e8.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).