Communication Lockdown™ by GuardKnox is a patented, threat-agnostic, deterministic cybersecurity solution for vehicles. It is a core architecture integrated in both hardware and software, designed to ensure communication security inside vehicles and with their environment. The system enforces a formally verified and deterministic configuration of communication among various networks of the vehicle, using a three-layer tiered approach to eliminate risks to the security of the vehicle and its passengers while maintaining flexibility and scalability for next-generation E/E architectures in software-defined vehicles. Communication Lockdown™ is certifiable to ISO 26262 up to ASIL D (the highest automotive safety integrity level for functional safety) and ISO 21434 (the standard for automotive cybersecurity engineering), and compliant with UNECE R155 regulations. It can be implemented as a centralized solution across all internal network communication, as a distributed and coordinated solution across the network, or as a local solution to protect single ECUs. The technology aims to provide protection against vehicle hacking and cyber attacks on connected and autonomous vehicles, thwarting safety-related attacks in real time without relying on heuristics or machine learning.