thumb|Kees Torn, 1991 Kees Torn (born 1967 in Oostburg) is a Dutch text writer and comedy performer. Career Torn started his cabaret performance in 1991, when he was studying at the Willem de Kooning
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 0x0f1ae7082dc49d43e57eb6027c32fc9e36847ddb78fd3cc1e1081acbc574d7e9. 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/c2d37fd8-8d64-4bef-aed3-85bd064aa6e7.json and https://artists.proofprofile.net/proofs/artist/c2d37fd8-8d64-4bef-aed3-85bd064aa6e7.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 0x5874a8cf1a2fdc1c2764fc13b98f03fe8422864fe116852da4b807186eb854ee. Chain 2 (Bitcoin): anchored in block 956745 (2026-07-05T05:33:35Z), 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/NLD321300716.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4d91ae41bd20b3f56b9ff62f3153c1a764537db1afc7c7cc5db866bc7d242e4. Chain 2 (Bitcoin): anchored in block 958746 (2026-07-19T15:36:35Z), 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/NLD321300721.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6a8d1d8ace659ec705ddc48c6bd523210dd0eb389ceae4eae0204d774316c60f. Chain 2 (Bitcoin): anchored in block 958169 (2026-07-15T16:16:18Z), 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/NLD321300722.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5de31a74405e16888d9935a4c2ce9437138d5c652c3cd7a3383a81ffe8eecb8. Chain 2 (Bitcoin): anchored in block 958842 (2026-07-20T07:48:27Z), 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/NLD321300724.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe678f0783bf7d9841e80b86fbe4e3419e9ddfb418c9d62d6f49440269b6711d2. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/NLD321300728.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5129f34030ac81d4bd0cb17ff55e759cd90a5f7b4aad368966d7bf7f6e94c49a. Chain 2 (Bitcoin): anchored in block 958319 (2026-07-16T20:12:32Z), 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/NLD321300729.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37f12842d94cfab1ad1a9177da4019af53d1ffb46bd772ffed7c9200da541347. Chain 2 (Bitcoin): anchored in block 958461 (2026-07-17T23:18:11Z), 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/NLD321300731.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xda98658721e84ee75b98c8b29dd44fda1669c4f2c98d1b08d27275da789a1713. Chain 2 (Bitcoin): anchored in block 958857 (2026-07-20T09:45:25Z), 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/NLD321300733.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3849529d385f592732624e995cedb8a37e2a5e8253d2c0deb167a960dab2b6a9. Chain 2 (Bitcoin): anchored in block 958153 (2026-07-15T12:03:04Z), 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/NLD321300738.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcad923217603985faf0f96b33cb9804e7acbc7d683ea556223dbe042fc6f61d0. Chain 2 (Bitcoin): anchored in block 958625 (2026-07-18T23:11:57Z), 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/NLD321300745.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x04ffcfbb13c4dab8870194513c030bfe62af5edeb60be4848d13baecafe9edc8. 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/NLD321300771.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b833656afbd73aafe8d2772dfe97f1ad4dc1f3eba5277b43811766fcb90c859. Chain 2 (Bitcoin): anchored in block 956620 (2026-07-04T07:11:13Z), 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/NLD321300796.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xec71723fe93c116cc106cfeed2670b4e1fe8b4c8f72a95075315ffaff9d4b1ae. Chain 2 (Bitcoin): anchored in block 958234 (2026-07-16T03:46:09Z), 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/NLD321300845.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x800ee2585dde1ed6024e6fa4da5770121dd544680f87505446b763febdb228f9. Chain 2 (Bitcoin): anchored in block 958746 (2026-07-19T15:36:35Z), 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/NLD321300846.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9f7020ed2b79ada36aef48e4c0142479008b7150d91cb3b0c1bfd8a09763045f. Chain 2 (Bitcoin): anchored in block 958621 (2026-07-18T22:59:44Z), 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/NLD321300847.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf6fb00a754efb9289373049be3ea476200d119ec6f41f4f237c04c58cd6c42c6. 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/NLD321300849.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe1298c68b3fa5832b3f8b29c0f0548bc2376f48416cf8417a1e11f4982823f9c. Chain 2 (Bitcoin): anchored in block 958746 (2026-07-19T15:36:35Z), 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/NLD321300851.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5dccd1736315c2ee1e08cb9b111a2dca730e126d60a08a327b144bfffb702513. Chain 2 (Bitcoin): anchored in block 959100 (2026-07-22T05:29:55Z), 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/NLD321300852.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfce44d812dd498a4014ed76341ebcc20003be1ef66dcd9ae44fa48860d973cc3. 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/NLD321300853.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd155fe19818ead1a5a256f562632f2e0c54e399e9cc2d846d70495e5e4228221. Chain 2 (Bitcoin): anchored in block 959105 (2026-07-22T06:33:30Z), 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/NLD321300855.