QR Codes for Product Authentication: Anti-Counterfeit Approaches

1. The Problem with Plain QR Codes

A standard QR code is trivially copyable. A counterfeiter can photograph the code and reproduce it on their fake product. Authentication requires something the counterfeiter cannot easily replicate.

2. Signed Payloads

Encode a cryptographically signed token containing the serial number, product code, and expiry. Verification requires the brand's public key. A copied token verifies correctly but the server flags the duplicate serial as counterfeit on the second scan.

3. Server-Side Scan Counting

Every scan is logged with time and location. Patterns like thousands of scans from one location, or simultaneous scans from different continents, flag suspicious activity. A legitimate consumer scans once at purchase.

4. Covert Physical Features

Pair the QR with a covert label feature (micro-text, security fibres, holograms) that cannot be reproduced by a printer. The digital QR check and the physical feature together raise the counterfeit cost.

5. Consumer-Facing Verification

Keep the verification flow simple: scan, see a confirmation screen with the product image and origin, and a "first scanned" date. Consumers trust clear, fast results.