PQAKA: Post Quantum Authentication and Key Agreement Protocol for Intelligent Internet of Vehicles over 5G

As Vehicular Networks evolve toward the Intelligent Internet of Vehicles (IoV), ensuring quantum-resilient security has become essential. The current 5G Authentication and Key Agreement (AKA) protocol, although well-established, relies on classical cryptographic primitives such as AES, Message Authentication Codes (MACs), and Key Derivation Functions (KDFs), which are increasingly vulnerable to advances in quantum computing. To mitigate this, we propose PQAKA, a Post-Quantum Authentication and Key Agreement protocol tailored for 5G-based Vehicle-to-Everything (V2X) communication. By integrating the National Institute of Standards and Technology (NIST)-standardized Module-Lattice Key Encapsulation Mechanism (ML-KEM), the proposed scheme achieves mutual authentication and forward secrecy against classical and quantum adversaries while maintaining compatibility with existing Access and Mobility Management Function (AMF)/Authentication Server Function (AUSF)/Unified Data Management (UDM) entities. Mapped to the 5G control plane, the protocol ensures that vehicles are authenticated before accessing Internet-based services such as navigation, traffic & weather updates, and over-the-air software delivery. Formal verification through ProVerif validates the correctness and security guarantees of the PQAKA protocol, while the informal analysis substantiates its resilience against a spectrum of adversarial vectors. Under hostile threat conditions, PQAKA achieves an authentication success rate of 72%, indicating its potential in quantum-resilient vehicular communication architectures.