Sombra (Spanish for shadow) may refer to: Alan Sombra (born 1994), Argentine footballer Martín Sombra (1938–2025), Colombian FARC militant Sombra, Ontario, a village situated on the St. Clair River
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 0x6641714260033196af08dece3aaef62027db11e1bece22b7a95379c87aa556be. 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/1c0842d8-2a87-40e3-b206-b9e2d9e609ef.json and https://artists.proofprofile.net/proofs/artist/1c0842d8-2a87-40e3-b206-b9e2d9e609ef.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 0x99514890761fa2448843bbc619c2b69abecc32c77ef807f6fd4c895c735ab159. 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/BRHW61300001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6d3bd24d444bd81983350f1d855ec5d788dd4ed19522afd8646cfdff38306d31. 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/BRHW61300005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdf65e0f63b00b040374e86e778793de10b66f064a2f8112a22698dfe78c72939. 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/BRHW61300009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc19f0fc7a528a986bebcaeac46914cede5aa923a16aafb121491dd668caa6f05. 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/BRHW61300004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd0a230b5a6c5bc50bde8d7aca4efc8ab9b42fb714727c1526c6cde5e7bd39d52. 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/BRHW61300010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe78d2e5ff27d6e05b654210a9a49daadadadc01f31d780f23ccb4bcb15d22c1f. 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/BRHW61300003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2446bfdfedc5a1ce88ede0454b147bbd68f868c488519ca64c83f9bcfac9caf3. 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/BRHW61300007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xecf3a8af0bba62e9007e4c05a947826d40ad6afe8a01a7a5dd4dc0de076b0f69. 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/BRHW61300006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a1b0999931c6d109b9c429c7b1ad7672ec476316852ac8562329d0fbf795ccc. 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/BRHW61300008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb01147493c0f5681217ba92e293e874d58aec104c060a2b50912ff06dc68efe6. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/BRHW61300002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ce3d00eebcc77678b6b8e2e97c4de621bc56b6d3ea8b4d3eda5c4522ef2fd5c. 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/BRT460800001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f63e255096994de66a5c18d51aabe12032c41a80fabdbd144478086f97717b6. Chain 2 (Bitcoin): anchored in block 959003 (2026-07-21T11:57:43Z), 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/BRT460800002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x068a157868dbecb9ede1cfe6d0ca2890be6e4f99aa83be7cf85b4957d1331ba6. Chain 2 (Bitcoin): anchored in block 958552 (2026-07-18T13:15:29Z), 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/BRT460800003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabb426e3700f7d537fb0e126e166784e9e83445de14523bc58fe7f9dc8e79e3a. Chain 2 (Bitcoin): anchored in block 958211 (2026-07-15T23:24:33Z), 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/BRT460800004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x038048d9e00933a92e7cf573b5b380e95aea681d09b19b250fa764a349c11b96. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BRT460800005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x21cd204682fa9a2228e22c5fe0f4905dd20854df5a7fdfdbdab71348facac51e. Chain 2 (Bitcoin): anchored in block 958176 (2026-07-15T20:07:42Z), 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/BRT460800006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xab5eb527a4e85062b33b1247f8ce2688e9f08c06f52922ff805b2bc56b7ea70c. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/BRT460800007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31c37d08d6787734c8d6ec755e32eadcd69cce66afd2b2c3da7be9e9ed4d0d07. Chain 2 (Bitcoin): anchored in block 958942 (2026-07-21T01:40:01Z), 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/BRT460800009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b843f728636d52ba52e0f5d93e6a71d3d249640db1f7c3044c49c254d657beb. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BRT460800010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9404f64c9e72320bc39118a17fb43e6deae1f09f4611740c14cc8639bc0985ea. 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/US7VG1717413.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x15844640867849d7d1637d52386a7cd3c05b0f649263bc966a61412586b84913. 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/BXAPN1800004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x814f1610292d9b083b41cd94921c5d399b711aad6bdbafe545d001e56d56dc21. 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/BR5VT1400046.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf77ea5fb20c86e95d1d56e730798f188aea7483b532e48334d89cf992a30ecd5. 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/BRHUM2400004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x63724ec5ea9971c8a94d4a0309211e41c7425be12dd8a72d883a9fc6b7160abc. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/BCMYE2219951.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c9d3c95c3a259c52e98f5abd2f568e7c6f8f6b18d7e30d9df5aa6230c58a250. 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/QMBZ92483635.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x12badf4c159753e0836d7eb34668bfbc09beaff16d61249cc25ed50d75e6ef92. 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/BRDAO0600004.