Angela Groothuizen (born 28 September 1959) is a Dutch singer and television personality. Her initial fame came as a member of the Dolly Dots. Biography Angela Groothuizen was born in Alkmaar, and ha
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 0x4f2252172bce50af623a24c29b9f40090e20f585a40d44510115cc8bb6e4861c. 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/21d638ed-42c4-4acc-b0cd-7e7de208493d.json and https://artists.proofprofile.net/proofs/artist/21d638ed-42c4-4acc-b0cd-7e7de208493d.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 0x55848a05d1f6eb751346291e7f32720ee4eb7f2bf560fdcb186716088a884e1a. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLDD71900007.
Alle Liedjes Van Het Sinterklaasmeezingboek
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6253bdbe4cb159e5aca71b5b9dc16a709bff5bfe67c67598570be07c5e285c63. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLDD70150004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5284702de0132a60a3b1df9137d699f394ff3cfd1d4c60499ada04e352fc7557. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLDD70150009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x02c83f43ef2007cb6e180e88368b51eb3aa4b3220ee26ac01a12076ea44a495b. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/TCAGZ2385494.
Het Beste van de Beste Zangers van Nederland (Deel 2)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd02f7e204857db210308047146d13d6d5c0dc5ab0291ede7310d811985c2b467. Chain 2 (Bitcoin): anchored in block 959123 (2026-07-22T11:35:32Z), 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/NLSU31100018.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x06c3b33d115894aebc2dee87d74645715e133b98b3077547b10eacbd911886d5. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/NLSU31200026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x626e292d30a0504b5c66fe759ba3b0becc990a8f40f56eb8da26f8bcc160f283. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/NLSU31400011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8b47c6325725a20c9f3ee45c0b06190892f9368490d96cd180a94e2e8ceb6502. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/NLSU31400039.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8445558de4f3c09d7468a3951b060403c518f73893c019c98660fd333f2fb59a. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLSU31200020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xad94e460e1f1ee97deef09b0434bb2cbbf759b1c1a6ab6c753a0f859eafe5a8a. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/NLMN21200002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd04e174eb288f58f950974cf1f9df438b3b578290afae5797f297ff0a0062a2a. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLMN21200011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe24f0f77a18cc512375e6b7c4d702f2176a9e6baa589d04d03361255dcbdeede. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLMN21200012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2e0fabc877b0b9f99dc8e9fcf10d1f9990d419dd8f8a6dbeeb871f74409a4c91. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/NLR1T2000190.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x278cb3f485c024d2e483ca63ba4401bc8b05e0572094740b0d4b4e6997a93d1e. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLP760600529.