Encryption

Encryption converts plaintext data into ciphertext using a key, making it unreadable without the corresponding decryption key. HTTPS (TLS) encryption is standard for internet communication, protecting data between browsers and web servers.

The most important fact about QR codes and encryption: standard QR codes (ISO/IEC 18004) have no data encryption capability. Text, URLs, Wi-Fi passwords, and any other data stored in a QR code can be read in plaintext by anyone who scans it. Error correction repairs damaged data but is fundamentally different from encryption.

The only practical encrypted QR code is SQRC, developed by Denso Wave. SQRC has a two-layer structure with public and private data areas, where private data requires a dedicated reader. It is used in manufacturingtraceability and anti-counterfeiting but is unsuitable for general consumer use. For typical applications, the safest design stores only an HTTPS URL in the QR code and handles sensitive data through server-side authentication.