K13 or K-13 may refer to: K-13 (film), a 2019 Indian Tamil psychological mystery thriller K-13 (Kansas highway) K-13 (missile), a Soviet air-to-air missile K13 gas fields, in the North Sea , a s
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 0xc33242baa597f255e4e6f7c98f6f08888bc1d7e9b863bd6d2576320bf7bddf64. Chain 2 (Bitcoin): anchored in block 953770 (2026-06-15T09:50:11Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c351535d-01d1-4ab7-b3fd-4d6fc3ce881a.json and https://artists.proofprofile.net/proofs/artist/c351535d-01d1-4ab7-b3fd-4d6fc3ce881a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).