Isa or ISA may refer to: Places Isa, Amur Oblast, Russia Isa, Kagoshima, Japan Isa, Nigeria Isa District, Kagoshima, former district in Japan Isa Town, middle class town located in Bahrain Moun
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 0xca64459d03f4f49a64b52b26db8aec542d50904e840d12e0b9980c6863411b2b. Chain 2 (Bitcoin): anchored in block 954516 (2026-06-20T07:04:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a2c6c084-8208-4bc6-8fff-50dd6b0f2221.json and https://artists.proofprofile.net/proofs/artist/a2c6c084-8208-4bc6-8fff-50dd6b0f2221.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).