Martin Ivanov (, born 11 July 1988, Sliven) is a Bulgarian judoka. At the 2012 Summer Olympics he competed in the Men's 66 kg, but was defeated in the second round by Sergey Lim of Kazakhstan. Refere
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 0x55f9ef2a2d63429cf3ce08537503a1c5ea42328c4b364c54b96a3c09b730d350. Chain 2 (Bitcoin): anchored in block 953714 (2026-06-15T00:43:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/81b748af-6c2d-4530-b187-290adc3221b6.json and https://artists.proofprofile.net/proofs/artist/81b748af-6c2d-4530-b187-290adc3221b6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).