Post-Quantum Testbed for EV-DER Communications through Grid Connected Home Energy Management Systems

The rapid growth of electric vehicles (EVs) and distributed energy resources (DERs) is transforming power systems into cyber-physical environments that depend on secure, low-latency communication. Home Energy Management Systems (HEMS) coordinate interactions between EVs, photovoltaic inverters, battery storage, and utility interfaces using standards such as ISO 15118, IEEE 2030.5, and IEC 61850. However, these protocols rely on classical public-key cryptography, including RSA and elliptic-curve schemes, which are vulnerable to future quantum attacks. Ensuring long-term confidentiality, integrity, and availability across EV-DER communication paths therefore requires a transition to post-quantum cryptography (PQC). This paper presents a reproducible PQC communication testbed tailored to HEMS-mediated EV-DER ecosystems. The framework integrates National Institute of Standards and Technology (NIST) standardised algorithms (ML-KEM and ML-DSA) into hybrid TLS 1.3 handshakes and evaluates their performance against classical baselines under realistic operating conditions. Four adversarial scenarios, man-in-the-middle (MITM), replay, downgrade, and fuzz/DoS are executed to assess resilience across critical communication links. Results show that hybrid PQC adds modest latency while maintaining the operational timing requirements needed for grid coordination. The findings demonstrate that quantum-resilient communication can be incorporated into existing EV and DER standards without compromising interoperability or performance. The testbed offers a practical foundation for PQC-enabled migration in future smart-grid environments.