Barka, Barca or Barqa or Barkah may refer to: Places Barca (ancient city), in eastern Libya Barka (Eritrea), a former province of Eritrea Barka, Divača, a village in Slovenia Barka, Oman, a town
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 0x069f1bd44e3e8424c001047c7c67b4abdfbed9da1f8e5dc3120405a593203fd1. 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/0f0a5282-fd01-4996-ba78-4e2e71161a84.json and https://artists.proofprofile.net/proofs/artist/0f0a5282-fd01-4996-ba78-4e2e71161a84.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).