I-f (also Interr-Ference) is the stage name of Ferenc E. van der Sluijs, a Dutch producer and DJ based in The Hague. Overview In 1997 he produced the track "Space Invaders Are Smoking Grass", which
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 0xb8e27ea44f54d95eae963ff4c52ea94cce3b0c49dfaa50ab8fa800319d52fc4d. 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/36d3d481-eb56-474f-a6d3-b702e3c93052.json and https://artists.proofprofile.net/proofs/artist/36d3d481-eb56-474f-a6d3-b702e3c93052.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Portrait of a Dead Girl (Part 1: The Cause)
The Amazing Run in the Victory Boogie Woogie Tunnel