thumb|A couple of coffee cups inserted into zarfs (, Swiss-made for Turkish market) A zarf (plural: zarfs, zarves; ; Arabic: ) is a cup holder, usually of ornamented metal, for a coffee cup without 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 0xcd034b8fa1a1e262e3c02be1eb987a6f0be88d5e35b6d44d32c13fd6ce882c0a. Chain 2 (Bitcoin): anchored in block 954014 (2026-06-16T22:46:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/321b809f-9358-4af2-ac95-cb410bac36bc.json and https://artists.proofprofile.net/proofs/artist/321b809f-9358-4af2-ac95-cb410bac36bc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).