Werner Fischer (7 November 1939 – 5 November 2025) was a German academic and engineer. Between 1980 and 1990, he served as vice-president and between 1990 and 2005 as the president of Karlsruhe Univer
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 0xee092709185be8b82029d4531b49abd299bcb71b465817ed9472de7738508548. Chain 2 (Bitcoin): anchored in block 953780 (2026-06-15T12:02:32Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d449ab8d-af54-4c6c-b334-ce345753ddae.json and https://artists.proofprofile.net/proofs/artist/d449ab8d-af54-4c6c-b334-ce345753ddae.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
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 0x184d7a064e0f0e819a637f501744b4391ea8b1c7a2be0b295a62aff228ef47e9. Chain 2 (Bitcoin): anchored in block 958742 (2026-07-19T14:09:34Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH6541636048 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xce1d0221402abaf98eaee6d8f3ce78d36cf3568fc19451977fec0ff33e3b02e9. Chain 2 (Bitcoin): anchored in block 959023 (2026-07-21T15:22:58Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH6541981629 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb20993d43d4f02521f871def4630033c1fc9964512d5fd5838954e03cfdce858. Chain 2 (Bitcoin): anchored in block 959107 (2026-07-22T07:19:23Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH6541982706 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe8241eaf7b5d1f1411bc49b2a97f8c270ff5d93a4c2410cd39f8f617d1ff1d03. Chain 2 (Bitcoin): anchored in block 958644 (2026-07-19T02:21:25Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH6541982708 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9ff62bec91de2f7aca58264c70cc05acae8abbd15067f914a9ed3aec3e56b15b. Chain 2 (Bitcoin): anchored in block 958621 (2026-07-18T22:59:44Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH3231630008 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x239fed807d68f1f530368ffaf890d3869bf67a08c63970c6ff78e2fea71f58ff. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CH3231930306 — a six-check JSON result.