Kamer is a given name. Notable people with the name include: Surname: Hiltje Maas-van de Kamer (born 1941), botanist at the Institute of Systematic Botany at Utrecht University Nadja Kamer (born 1986
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 0xde97b35701709b6070e3caa967a33c23ee1cb08ed71028edd3b984d1aa868b76. Chain 2 (Bitcoin): anchored in block 953733 (2026-06-15T03:12:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9709a8e7-9090-4906-8e9f-17f48785cfe9.json and https://artists.proofprofile.net/proofs/artist/9709a8e7-9090-4906-8e9f-17f48785cfe9.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 0x6060e3cd7f494d2b97efd874c867b2ac7c4c39aa665a025b44525445ce5970d0. Chain 2 (Bitcoin): anchored in block 958585 (2026-07-18T17:05:16Z), 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/TCAEA1828944.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfbb39b8c777b9c08cc634df5a058cc25461fd29f9a50784ff8893d849c5a6c6b. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/USHM21981066.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd2dcef16c82750a5e66a58b3c52cc998e9116bd658319d2453645620677d7eea. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/QZES82090873.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x960e9b94c6984018feadea13873bbad0267dfcb8b93a963760e48769b0911cc9. Chain 2 (Bitcoin): anchored in block 958432 (2026-07-17T15:43:17Z), 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/QZNWQ2044404.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2857430a593a21869f63ac771cb7d55e6ee6693d9d2dce7ad76365c8475d1a1c. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/TR0012300212.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xba99e91d63622a082d1c39e6fbcfff88005f9841d561a739ee4b5bd4238a147a. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/TR0012300279.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x53268bb6bdcb5b2f16a1392cbacfc9d1f4a57b02354bacc3e50cd787f1f4594c. Chain 2 (Bitcoin): anchored in block 958931 (2026-07-20T21:15:01Z), 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/TRA162500214.