TraceGuard: A QR Code and Blockchain-Based Framework for Counterfeit Product Detection and Supply Chain Transparency

Counterfeiting causes measurable revenue loss and erodes consumer trust across manufacturing sectors, yet most anti-counterfeiting deployments still depend on centralized product registries that a single administrator can alter without detection. This paper proposes TraceGuard, a verification framework that pairs a per-unit QR code with an immutable blockchain ledger so that authenticity checks do not depend on trusting the manufacturer's own database. Each product is assigned a hashed identifier at the point of manufacture; the hash, together with batch and ownership metadata, is written to a permissioned blockchain through a smart contract, and the QR code printed on the product encodes only a lookup reference, never the underlying data. A scanning application resolves the reference against the ledger and returns a verification result along with the product's custody history, so a buyer can see not just whether a code is genuine but whether it has already been scanned as sold elsewhere. We describe the smart contract design, the QR encoding scheme, the mobile verification workflow, and a batch-transfer mechanism for supply-chain custody changes, and we evaluate the system on constructed product batches for verification latency, duplicate-scan detection, and resistance to QR cloning. The results indicate that ledger-backed verification catches duplicate and out-of-sequence scans that a static-database approach would miss, at a modest latency cost.

Keywords - Counterfeit Detection, QR Code Verification, Blockchain Traceability, Smart Contracts, Supply Chain Transparency, Product Authentication