Abstract
This paper describes a simpler version of the cryptographic system designed to secure the communications of low-power Internet of Things (IoT) devices operating in low-resource, low-computation, and low-speed environments. The system in question is based on a hybrid cryptographic model that includes a certain type of hashing with Deterministic Finite Automata (DFA) and key creation through a chaotic dynamic system, the Lorentz attractor. This model strikes a good balance of tradeoff between resource simplification and dependability. A prototype system was developed first on the Arduino Uno, then later improved on the Wokwi simulator, which enabled the simulation of the IoT devices’ actual operating environment. The automata perform a hashing which is both robust and deterministic, which helps to confirm the integrity of the data. The keys generated by the Lorentz system provide deterministic yet highly sensitive keys to perturbations ensuring total unpredictability. The encryption method used is also quite simple, and that is the XOR operation. This makes the entire system compact, fast, easily reversible, and resource efficient. This research shows how useful automatism and chaos theory are in developing cyber security measures for the Internet of Things (IoT) at the embedded system levels.