thumb|Leif Sylvester Petersen Leif Sylvester Petersen, (born 18 April 1940) in Copenhagen, also known as Leif Sylvester, is a Danish painter, graphic artist, musician, and actor. He originally trained
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 0x4a97dcd615edc397d5d21f51b76be8175000612272bf10ee98b02dea81d71233. Chain 2 (Bitcoin): anchored in block 953889 (2026-06-16T04:57:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0e34a3eb-d5ea-4ea4-9d17-723e62aa3650.json and https://artists.proofprofile.net/proofs/artist/0e34a3eb-d5ea-4ea4-9d17-723e62aa3650.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Alle Tiders - Clausen & Petersen med Eva Madsen - Mormors Kolonihavehus
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 0xff4c0d0a7166d19222c8da0e7c1af496888fca18a6f941969b9ee44a4a0a7415. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), 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/DKUM70600345.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x809cc9a3941535f3d39577cf45738372e6dc7c7fdcca6d2ddec38648a25c0244. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/DKUM70600346.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4593a62cac23d16afc0b4f36c3ef6d1468d933024363f08848abc89d050535f1. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/DKBKA0300639.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f001f7cf5137cd6026bdd9e82bd7d69b8dc7a2d48c9ca43c97b6f74d08d6064. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/DKBKA0300629.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x76c3d1cb9574563d25cc2cab5c7366f66ae47f5cbf658c10af05acc70efd519b. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T15:05:02Z), 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/DKUM70600343.
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 0xbe4634a72f77519f16a703a4502846b5fd3e065b39fda85bc5da083ca3df75c3. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/DKUM70600342.