Joaquín Salvador Lavado Tejón (17 July 193230 September 2020), better known by his pen name Quino (), was an Argentine cartoonist. His comic strip Mafalda (which ran from 1964 to 1973) is popular in m
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 0xcefe61cd8b3f0b5c886287bfe956f668afb0ee2d8f0eeb65ff1dc65295c3ef72. Chain 2 (Bitcoin): anchored in block 953984 (2026-06-16T18:08:34Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2c61cc53-59b5-431c-a82a-a226ee78fbee.json and https://artists.proofprofile.net/proofs/artist/2c61cc53-59b5-431c-a82a-a226ee78fbee.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).