Hanoi ( ) is the capital and second-most populous municipality of Vietnam. It encompasses an area of , and as of 2025 has a population of 8,807,523. Hanoi had the second-highest gross regional domesti
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 0xd3186efd2951f0bd85c64059d84e72d831d61190a9b725fd8b3abae7cb7c5f39. Chain 2 (Bitcoin): anchored in block 953932 (2026-06-16T11:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1fcef5c1-b3cf-4717-a466-f7ca3ab86b9d.json and https://artists.proofprofile.net/proofs/artist/1fcef5c1-b3cf-4717-a466-f7ca3ab86b9d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).