thumb|Nina and Frederik in Amsterdam, making a TV show in 1967. Nina & Frederik were a Danish–Dutch popular singing duo of the late 1950s and early 1960s. Their repertoire consisted of a blend of folk
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 0x0cb4131cec43546709320b9ae0b7017a6fae64e197b6944beab8f77487b9b98f. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/03b49ac7-b175-40f6-938b-f8729083f0be.json and https://artists.proofprofile.net/proofs/artist/03b49ac7-b175-40f6-938b-f8729083f0be.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 0x672e8835ccd4e9f1edff7a30305957462ef549bea1862ce3a2340853f74dc5c3. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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/DEXO52485436.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe70502a6c7affd9569b6905f28993e4d5e32ddc68dab978b2e46c2538f4812d6. Chain 2 (Bitcoin): anchored in block 958805 (2026-07-20T02:22:58Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEXO52485487.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x90b9d15901221dc1a3d55b3bbba1881a6ab34e113e49513a448148e7d48de5ea. Chain 2 (Bitcoin): anchored in block 959144 (2026-07-22T15:38:35Z), 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/DEXO12375474.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x07f1dbeedf6f1612baa9ceaba474a13162711a6f28efed61f85ca4ca0262f033. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/DEXO12375479.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa30e57cf44255f4a2953b1e8d859c04ff8ea91b60c21f7d1e023b15e9239e01e. 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/DEXO12375484.
Vintage World Nº10- EPs Collectors "Oh, Pecador" "Oh, Sinner Man"
Vintage World No. 99 - EP: Mes Compliments, Cherie
Vintage World No. 101 - EP: When Woman Say No She Mean Yes
Vintage Movies Nº 13 - EPs Collectors, "Formula For Love"
Introducing the Fabulous Nina and Frederik
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc07ddc2212f1b7f72faa13b8f4c2186d71911d876ece2f4549cd4963619de220. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/USLZJ2111178.
Lad Os Flyve Til En Stjerne [Det Bedste Af Det Bedste]
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbf1e8601436de68bb612ec3cb7515ce3ef1c8a4d9e349a09ba0283a15c92be24. Chain 2 (Bitcoin): anchored in block 958774 (2026-07-19T20:03:27Z), 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/DKABA1103801.
The Nina & Frederik Collection: Listen To The Ocean
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64176eb1a75a39b4acbab242f4ad326d540a2aaa577cebf6e50d56a2dd0ab12c. 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/DKABA1103888.
Jamaica Farewell And Other Songs Of The Islands
Christmas At Home With Nina And Frederik
Christmas At Home With Nina and Frederik
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x862366f2dd53ab0de11e6b9ff9619510897eb69defac8cadb6fcd4ad4ba9203d. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/GBURZ1101445.
Nina & Frederik. Sus Grandes Éxitos (1958-1964)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xef3c79d25ba5f136b057c850b0aafed65a9e06afd8057612557628ecc9ff6185. Chain 2 (Bitcoin): anchored in block 956551 (2026-07-03T21:18:05Z), 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/DEKB71598937.
Frohe Weihnacht / Merry Christmas / Joyeux Noël / Vrolijk Kerstfeest
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe0a0b3a66b94a5fec5dba5bd921bb312819268b98ef52a1a3ce07258b714a461. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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/GBH5G1800528.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x053bd8d741a8d037a2d88a6144a7ed38a92c31c9992def13e19fa6f2f7bd593c. Chain 2 (Bitcoin): anchored in block 958383 (2026-07-17T08:20:01Z), 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/GBH5G1800532.
Jamaica Farewell and Other Songs of the Islands
Les idoles de la musique danoise : nina & frederik, vol. 1
Nina & Frederik Sing the Banana Boat Songs
Essential Classics, Vol. 307: Nina & Frederik