Walter Pfeiffer (born in Beggingen in 1946) is a Swiss artist. Life and career Walter Pfeiffer was born in Beggingen (Switzerland), in 1946 and has been producing since the early 1970s. His portrait
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 0x49da0652555a4622f18994b6117895c421c2f50c8a6f8aa4259554af005eedd3. Chain 2 (Bitcoin): anchored in block 953875 (2026-06-16T02:12:46Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/07720dd2-ba33-4990-b319-1c8c9ba598a5.json and https://artists.proofprofile.net/proofs/artist/07720dd2-ba33-4990-b319-1c8c9ba598a5.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Bach, JS: Concerto for Two Violins in D Minor, BWV 1043: I. Vivace
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 0x7fe831875adf7b29424893de8304c889cdaff402bc19a5eee89ef3692170791d. Chain 2 (Bitcoin): anchored in block 960296 (2026-07-30T19:11:09Z), 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/DEA806700101.