Quantum-Secure Autonomous Factories: Hybrid TLS 1.3 for Inter- and Intra-plant Communication

Given recent advances in the field of quantum cryptography, cryptographic agility is essential to protect data at rest and in transit. We consider hybrid key exchange and authentication in the framework of the TLS1.3 protocol. Traditional hybrid mode, which uses classical and quantum-safe algorithms together to secure data in the event of one of the algorithms being broken, has been a subject of research for a few years now. However, there are certain engineering challenges that come with using more than one algorithm in the framework of the TLS protocol. In this work, we propose a different hybrid mode that allows seamless negotiation between classical and quantum-safe algorithms. The proposed hybrid mode has different goals from the conventional hybrid mode and could be an excellent solution for entities not required to use standardized cryptographic algorithms and can be used in the timeframe when quantum-safe algorithms have been standardized but certain endpoints have not yet transitioned to post-quantum. We discuss conventional and proposed hybrid modes, described the proposed solution in detail, and briefly review engineering challenges associated with each hybrid mode.