Umbrtka is a metal band from Plzeň, Czech Republic. The band describe their music, which incorporates black, doom, industrial metal elements and is influenced by Czech underground, as 'grey' metal. Th
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 0x6921cf10592a5bc56112abce87c37df898c8739cdbb6a5e5acbfd5c7c5d80661. Chain 2 (Bitcoin): anchored in block 953997 (2026-06-16T20:07:57Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/18e7f628-9d76-4ecd-a0e6-837f38fd55ff.json and https://artists.proofprofile.net/proofs/artist/18e7f628-9d76-4ecd-a0e6-837f38fd55ff.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).