Cairo is the capital and largest city of Egypt and the Cairo Governorate. It is home to more than 9.8 million people. It is also part of the largest urban agglomeration in Africa, the Arab world, and
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 0x1a1d77642d5d3f8b6914c5fbd523c709aa0c3592ffd52352b63f6d47927c06a1. Chain 2 (Bitcoin): anchored in block 953617 (2026-06-14T09:00:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1be0834d-5d7d-4c75-a8c4-a06d9a4e250b.json and https://artists.proofprofile.net/proofs/artist/1be0834d-5d7d-4c75-a8c4-a06d9a4e250b.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 0xf65f59e53b018ffa5bbe16ff8d1ce30e0a25ffa85deff0a334fd03a25e99fd9f. Chain 2 (Bitcoin): anchored in block 958700 (2026-07-19T08:09:50Z), 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/QZFZ62226318.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe886666bd466b84ba08b8299d5c580dd58aa4c62d7d96e9cecbec478ceabb421. Chain 2 (Bitcoin): anchored in block 958695 (2026-07-19T07:37:00Z), 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/QZES52291230.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4393f8fe0a015269c0dec7e2a248389cd804b9bfcff24e57735071cf04fb025d. Chain 2 (Bitcoin): anchored in block 959026 (2026-07-21T15:38:13Z), 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/QZRP52213169.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x24d91ce8055913c85aa0f833ff850eb47666e6d63ee3f0f56e823ff2b62854c3. 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/QZHN72335721.