K28 may refer to: K-28 (Kansas highway) K-28 trailer, part of the SCR-268 radar system Rio Grande class K-28, an American steam locomotive Sonata in C, K. 28, by Wolfgang Amadeus Mozart K27/28 Be
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 0xb01b8b76e3cc449ea2ce2b0df69dc4c2ffb394984633fb54ac46ab916ed421fa. Chain 2 (Bitcoin): anchored in block 953648 (2026-06-14T15:20:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4177bd5c-c631-4075-b921-2769bed34cf1.json and https://artists.proofprofile.net/proofs/artist/4177bd5c-c631-4075-b921-2769bed34cf1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).