Quantum Meets Agile: Crypto-Agility for a Post-Quantum World

As the automotive industry transitions toward software-defined vehicles and connected ecosystems, cybersecurity becomes a critical design pillar. A pressing challenge emerges with the advent of quantum computing, which threatens to render existing cryptographic standards such as RSA and ECC obsolete. This paper addresses the need for quantum-resilient security architectures in the automotive domain by introducing a combined approach using Post-Quantum Cryptography (PQC) and crypto-agility. Unlike traditional static cryptographic systems, our approach leverages agile architectures that enable seamless integration of new cryptographic algorithms as they emerge. Central to our work is the role of Hardware Security Modules (HSMs), which provide secure, tamper-resistant environments for cryptographic operations within vehicles. We explore how HSMs can evolve into crypto-agile and quantum-safe platforms capable of supporting hybrid and post-quantum algorithms, allowing secure transitions without hardware replacement. The novelty of this work lies in the development and validation of a first-of-its-kind operational prototype that supports current cryptographic standards (RSA/ECC) and is designed for plug-and-play migration to PQC. Our architecture enables automakers to maintain long-term security while reducing operational disruption and costs. We followed a system architecture methodology, integrating both software and hardware HSMs, and evaluated key performance metrics such as latency, key negotiation time, and re-keying efficiency under hybrid cryptographic conditions. Results show that crypto agility can be achieved with minimal overhead, demonstrating feasibility for real-world deployment. The findings underscore the urgency for proactive adoption of quantum-safe security practices, as vehicles produced today will remain in service long after quantum computers become viable. By adopting crypto-agile designs, automakers can mitigate long-term risks and ensure resilience against future cryptographic threats. This paper provides both a technical roadmap and a practical demonstration to guide the automotive industry toward a secure, quantum-resilient future.