Quantum Cryptography for Secure Communications in Industrial Mechatronics and Embedded Systems

This paper proposes a unique paradigm for strengthening secure communications in industrial mechatronics and embedded systems by seamlessly combining post-quantum and quantum cryptography. Implementing quantum key distribution (QKD) protocols, notably BB84 and E91, which allow parties to generate securely shared keys over untrusted quantum channels, forms the system's foundation. A thorough analysis of these QKD algorithms reveals they can offer guaranteed eavesdropping detection and unconditional forward secrecy, two features necessary for building secure, solid communications. The paper incorporates advanced post-quantum cryptographic techniques developed during the NIST Post-Quantum Cryptography competition to address the imminent threat of widespread quantum computing capabilities. These include the lattice-based CRYSTALS-Kyber and hash-based SPHINCS+ algorithm. The framework utilizes an advanced hybrid technique that provides a robust compound security solution by deriving subordinate keys for the post-quantum cryptographic primitives from the QKD-established root keys. Moreover, the study suggests an automated key management system that effectively manages the essential lifecycle, including creation, distribution, revocation, and rotation, while guaranteeing adherence to current industrial security requirements, including IEC 62443. The speed of crucial cryptographic processes, such as key exchange, encryption, decryption, signature, and verification for the quantum and post-quantum components, is measured by performance assessment. It weighs trade-offs versus established techniques like an elliptic curve and RSA cryptography. Through enhancing the security and resilience of critical industrial infrastructure, such as manufacturing facilities and power grids, this study lowers the chances of system failures or malicious assaults, improves public safety, and prevents disruptions.