Quantum-Safe Smart EV Charging and Secure Billing System Using IoT and Post-Quantum Cryptography

The rapid growth of electric vehicles (EVs) has created a strong demand for secure, intelligent, and reliable charging infrastructures. Most existing EV charging systems rely on classical cryptographic algorithms such as RSA and Elliptic Curve Cryptography (ECC), which are vulnerable to attacks from future quantum computers. This paper presents a quantum-safe smart EV charging and secure billing system implemented using low-cost Internet of Things (IoT) hardware and post-quantum cryptographic (PQC) algorithms. The proposed system integrates RFID-based vehicle authenti- cation, real-time energy measurement, and secure offline billing. An ESP32 microcontroller controls the charging process through a relay module and collects voltage, current, and energy data from an energy meter sensor. Secure communication between the ESP32 and a Raspberry Pi server is achieved using CRYSTALS- Kyber for key exchange and CRYSTALS-Dilithium for digital signatures. The Raspberry Pi stores charging session logs and generates tamper-proof billing records based on actual energy consumption. The entire system operates offline on a local Wi-Fi network, ensuring privacy and reliability. Experimental results demonstrate the feasibility of deploying post-quantum cryptography on low-cost IoT hardware for future-ready EV charging systems.