Tobias Klein (born 23 March 1982), also known as Tobi Klein, is a German former professional tennis player. Klein, a native of Baden-Württemberg, was a collegiate player for the University of Alabama
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 0xf3ad046dd7d8c33d59adbd87ea8d21f4671d153f17ec8f2c22aa5fe2a7b2c4c4. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8e6c0a98-16d3-4fea-8428-b3dd4eaf83dd.json and https://artists.proofprofile.net/proofs/artist/8e6c0a98-16d3-4fea-8428-b3dd4eaf83dd.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).