Soju (English pronunciation: ; ) is a clear and colorless distilled alcoholic beverage from Korea, traditionally made from rice, but later from other grains and has a flavor similar to vodka. It is
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 0x14fdf96efcff75dc61e9691e663468978e7b27e1d331a84d48be3aa0940fe50f. Chain 2 (Bitcoin): anchored in block 953867 (2026-06-16T01:09:47Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/059238f1-1b20-481f-b0f1-fe2d5bb558d1.json and https://artists.proofprofile.net/proofs/artist/059238f1-1b20-481f-b0f1-fe2d5bb558d1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).