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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x36c12579bab1b29d08cede85b7f7c82b23ff1625195399ff9407c18d79c9ef31. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9b080781-c1f5-4b07-9ce0-7b8eac914e2e.json and https://artists.proofprofile.net/proofs/artist/9b080781-c1f5-4b07-9ce0-7b8eac914e2e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd9203a329eb7b79392abb08a630407d56c45a0f7ff228376f5ebef9be94bde4. Chain 2 (Bitcoin): anchored in block 957556 (2026-07-11T11:14:07Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEK599826903.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x09fdfb2b05c91a7e3378e4d32d4ab8973266bcde4180b6b22962868680b105e8. Chain 2 (Bitcoin): anchored in block 956560 (2026-07-03T23:28:02Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEK599826909.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6d6b3604b640ac2fbffe93d2d724fdb808520ab57f14bfad9ff2041bdecbd577. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEK599826911.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e69a3d22dc7c6ff600a1c9b5814dbf059274c1269e7499e061c3497ea400e48. Chain 2 (Bitcoin): anchored in block 958194 (2026-07-15T20:32:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEK599928301.
Floating Away in a Hole Darker Than Yours - Melvin White Remix
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdebb245a9cce6af97fb44ef1c722e118d1bef00098187b951ef7d11099c2b231. Chain 2 (Bitcoin): anchored in block 958517 (2026-07-18T07:54:29Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEK599928311.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x21f23bbe900eac4c08d765dccbcb8c6bffe18e6c2d7de5a4e1f126d152337f61. Chain 2 (Bitcoin): anchored in block 958461 (2026-07-17T23:18:11Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEK599928312.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f072beee62c9388ac4f98a69145faafe9c55720e536c2e3b032e2e5dd3b666c. Chain 2 (Bitcoin): anchored in block 956351 (2026-07-02T11:38:34Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/KRA491600322.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x376615fff4cddb934065792b931ea9f82f8e562e42b04809d2930463ab7f9529. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/US2J70400505.
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp 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