Isgaard Marke (born 1972 in Husum, Schleswig-Holstein, Germany) is a classically trained singer, who in 2003 participated in the German pre-selection for the Eurovision Song Contest and reached sevent
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 0xa5b2834a81fcf64bbe87ae8f80a7831d46091a9b0ff3b1bf6ea8abea727e5f1f. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/6f689fff-27e4-4888-af76-4f8d9c7bd6bb.json and https://artists.proofprofile.net/proofs/artist/6f689fff-27e4-4888-af76-4f8d9c7bd6bb.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).