The doina () is a Romanian musical tune style, possibly with Middle Eastern roots, customary in Romanian peasant music, as well as in lăutărească music. It was also adopted into klezmer music.The Jews
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 0x46dba4168c4760784c443ba606119cd10627a4a92700028b5028853a4818b06d. 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/c9669c0b-00f6-43ec-bd2a-f44362f1511a.json and https://artists.proofprofile.net/proofs/artist/c9669c0b-00f6-43ec-bd2a-f44362f1511a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).