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 0x6f54d0feb7cf4404a7e81f7cbf3b81e5007c4dc2e4ce2aa40af832029c7e9551. Chain 2 (Bitcoin): anchored in block 953812 (2026-06-15T17:06:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f812579b-094f-4221-b119-06e002439dbd.json and https://artists.proofprofile.net/proofs/artist/f812579b-094f-4221-b119-06e002439dbd.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 0x2e0a6b45080e70df0c67aa84638803e840caaf4a3eb3082c58ac318e6dcf5f81. 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/BRD1E1900044.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa779c70e59369f6c3650fa5e462fac31d81bb15118e1422e7200ae2c3f2a083f. 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/BRD1E1900045.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52af2f48b38760c1414892b9b7f996d287e550d8d6fd075657c1fb13cf27c8fe. 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/BRD1E1900046.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb3f9c1ff6187777f46defdd8bf48d7c684f81fbf48177cbdea414961a558084b. 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/BRD1E1900047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xce28bb2f79ceff578b6ef35668e05774f6d63544b79433908af576c72964fd48. 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/BRD1E1900048.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7fb97f5c381d82b0674cdf076cb4a9380a0b7d881a8fa5ec3b6ecd2083dc4026. 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/BRD1E1900049.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0618b1ed9bdd30938e3269470f4fd5dc865bb37da354e79da2731d6bf021d329. 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/BRD1E1900050.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6023cf758e361e5e91182472ad0c3297de9dbb67bc61a738bc773eca10a2fc96. 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/BRD1E1900051.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xacac8ec1180d81888eba59c73d8a136979249ac43f2e0ea868669084c0ab3ad5. 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/BRD1E1900052.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf93013030de35bd70da89751a1609062ffe88d3ffe85dc8dc3b18e2c5c6d709. 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/BRD1E1900053.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfe21c117359759f43521f69df3d9d7214f5d45d2e269c685c5a3bcd7a5bc05da. 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/BRD1E1900054.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1caec55c66c254e043330c25e031627f2f4c57bc2cdf5e8bca8b6cb012016277. Chain 2 (Bitcoin): anchored in block 960203 (2026-07-30T03:35:13Z), 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/BRD1E1900055.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4ec30a231204f7568c5a51315770a56da2ee068e47b1da320bdc5325339d733f. Chain 2 (Bitcoin): anchored in block 960360 (2026-07-31T06:42:11Z), 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/BRWS61700001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1dad3cdc55779e321b3c71bb235e3546d9b91b6d278d6d8f16606c6801d3d082. 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/BXP9D2100066.