The Albertina is a museum in the Innere Stadt (First District) of Vienna, Austria. It houses one of the largest and most important print rooms in the world with approximately 65,000 drawings and appro
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 0x3fc18d4157f518b5362d8187ebfbdf9cb999977c84b55bd03e99fb8b44cbd0ed. Chain 2 (Bitcoin): anchored in block 954603 (2026-06-20T21:47:54Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c2894b68-ecb0-4174-a0bd-612cbefa7b6e.json and https://artists.proofprofile.net/proofs/artist/c2894b68-ecb0-4174-a0bd-612cbefa7b6e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).