Civia is a class of electric multiple unit trains built by CAF and Siemens for the Renfe Cercanías commuter railway networks in Spain. The first units entered service in 2003. The Civia train concept
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 0x237135e6cfe94f9bf133c32c931e13de78429e7e684625243cbaa940d01acfc0. Chain 2 (Bitcoin): anchored in block 954346 (2026-06-19T03:51:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/940b2724-8d08-44b3-8f52-8823517cff6f.json and https://artists.proofprofile.net/proofs/artist/940b2724-8d08-44b3-8f52-8823517cff6f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).