Slavin Slavchev (, born 7 March 1991) is a Bulgarian singer and songwriter currently a lead vocal and bass guitarist in Julian's Laughter. He is the winner of the 2014 season of Bulgarian X Factor. C
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 Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x35f17f5a3c24c5f43f2911d268a6eab91f21e669fcde11da7c82a738aff541b6. Chain 2 (Bitcoin): anchored in block 954035 (2026-06-17T02:39:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3cc91fca-d927-41ce-b5e3-7e6dbbb04757.json and https://artists.proofprofile.net/proofs/artist/3cc91fca-d927-41ce-b5e3-7e6dbbb04757.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.