Fenster is a surname, from the German language word for "window". Notable persons with this surname include: Della Dumbaugh, formerly Della Fenster, American historian of mathematics Aaron Fenster,
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 0x4e31de2725bdc03c3064c08afb416c5ea35caebb5d586ee20174ac53e2d5b718. Chain 2 (Bitcoin): anchored in block 953641 (2026-06-14T13:54:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3c29cb74-c3ff-4405-be4e-95f9122e08d6.json and https://artists.proofprofile.net/proofs/artist/3c29cb74-c3ff-4405-be4e-95f9122e08d6.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 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 0x131bbde2e76581892f6bc92da2711ff779a898da42132b9ce87f787294b7b5a0. Chain 2 (Bitcoin): anchored in block 956857 (2026-07-06T01:26:17Z), 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/DEX261513905.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd8e43ff2515084573c3d0dc354169f99b70297e65c90b6d21ed79189966c937f. Chain 2 (Bitcoin): anchored in block 958487 (2026-07-18T03:43:59Z), 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/DEX261513908.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x741737ec139ede3b6632ae6221ffc2a9af60fdee6018dc7a1c883ce23c8bf249. Chain 2 (Bitcoin): anchored in block 959096 (2026-07-22T03:48:36Z), 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/DEX261866601.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x70ae068d130354350988a8bd7d4903323a39950b10a48d2b300f4b8a721de29d. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/DEX261866607.