Didar (, also Romanized as Dīdār) is a village in Hesar-e Valiyeasr Rural District, Central District, Avaj County, Qazvin Province, Iran. At the 2006 census, its population was 358, in 88 families.
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 0xf3a85eddc35e7e6a70a8295351571af78afa6e8e496ff9cc830520735c7e9d99. Chain 2 (Bitcoin): anchored in block 953778 (2026-06-15T11:57:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d2bee78c-b59b-4e34-9fe3-340719e8a7cc.json and https://artists.proofprofile.net/proofs/artist/d2bee78c-b59b-4e34-9fe3-340719e8a7cc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).