xDT (aka KVDT) is a family of data exchange formats that are used by physicians and health care administration in Germany. They were created by initiative of the Kassenärztliche Bundesvereinigung (Nat
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 0x67e45e5f7ef1baef484f8483cb3ac6a6d4201c522a8cbc036cb14b5e8f7c75f9. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b54555b0-538f-4a79-8a9f-be446fff69f8.json and https://artists.proofprofile.net/proofs/artist/b54555b0-538f-4a79-8a9f-be446fff69f8.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).