MAXXI (, 'national museum of 21st-century arts') is a national museum of contemporary art and architecture in the Flaminio neighborhood of Rome, Italy. The museum is managed by a foundation created by
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 0x29247e29ad62dd58a09f9b9d69a8d42ac8e6e8e3c414c007e003ff6aaaaca088. Chain 2 (Bitcoin): anchored in block 954017 (2026-06-16T23:38:33Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/36771a04-7527-4ce5-a4c2-8e1c52858643.json and https://artists.proofprofile.net/proofs/artist/36771a04-7527-4ce5-a4c2-8e1c52858643.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).