Slagter is a Dutch surname literally meaning butcher. Notable people with the surname include: Carolina Slagter (born 1994), Dutch water polo player Tom-Jelte Slagter (born 1989), Dutch cyclist See
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 0x742c67a6e815610e93cbf3f8f78353864eafc22789fb95c33cdb0163a3ba3787. 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/90dad76a-15f7-4b21-a6ac-92ec5807e291.json and https://artists.proofprofile.net/proofs/artist/90dad76a-15f7-4b21-a6ac-92ec5807e291.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 0x0515f365d59ea079beacd372035bca6e7f322641505a2bcbf0ee80ff3bbfe94c. 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/QZHN32420028.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x368a73e7746602d84e3f79209b3cb623c3eeccf3bc6e5cc256ca1ea089af9ba0. Chain 2 (Bitcoin): anchored in block 960160 (2026-07-29T22:48:59Z), 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/QZHN32420029.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc0ba9d01241dac1290ad57335d60694bb616b4ca9df3f1a650415d013e68a011. 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/QZMEM2353989.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62ff7ae79e0476a95183c718ec16197e22b7f0514d7a9b9806825170b63061d9. 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/QZHN32420031.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3f42c9b04f33a73a7648b7b41f09206d57748438ddfda9573c5cee1b7c73bd2f. 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/QZHN32420032.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7293cc4a142e1ba116ea8ccc074b571913179c0ad1c858aa733541f923adfcff. Chain 2 (Bitcoin): anchored in block 960410 (2026-07-31T13:50:38Z), 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/QZDA42203623.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6ad3c92f14f756e64f903c561854ebcc06428ad108b453ade8a19c804c21cabd. 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/QZDA42203624.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd50804170a5a31e137efea08258542b39f12f6f168db2bb8e1a2f2eb2a452862. 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/QZDA42203626.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x75cc8bf6cda2c58cf7b802e15bdae1b12ef89d4413f9dc29e29310b18872beac. 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/QZPLR2101916.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x976adfe630df31471de8943963c1ab3bba9629bb1ac61086dd79f64b7358a58c. 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/QZPLR2101917.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9b8e3420754e9d02aba9c710dfc569a060a36957f7d01db34d1eb613bc33c66. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/QZPLR2101919.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd09e282b3faec86b1d7226bf47f796fc5a713c1445259a8a434010467fb5eb86. Chain 2 (Bitcoin): anchored in block 960376 (2026-07-31T09:09:19Z), 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/QZPLR2101920.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7f40f1519a25aa28a176ea18830fee5e1b51b3066c0bb3078b44b16f7356f121. 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/QZMEM2164899.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1cad713e117cf7acf7449be3f4ca610b8868f8e1184fa5d6c2db386ccf56c101. Chain 2 (Bitcoin): anchored in block 960506 (2026-08-01T03:50:58Z), 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/QZMEM2164900.