Codrina-Victoria Lisaru

A peer-reviewed journal of applied informatics that covers a broad range of topics, especially dealing with the social and business aspects of informatics.

Fuzz testing is a key verification technique for identifying robustness and cybersecurity weaknesses in automotive electronic control units (ECUs). However, conventional CAN-based fuzz testing suffers from extremely low acceptance rates because randomly generated frames often violate protocol constraints such as counters, check-sums, and state dependencies. This study addresses the test-preparation bottleneck by proposing an AI-assisted approach for automated identification of stable operational system states from Controller Area Network (CAN) traces. These states can serve as valid starting points for mutation-based and model-based fuzzing. CAN traces generated in a Hardware-in-the-Loop (HIL) environment were analyzed using multiple publicly accessible large language model (LLM) systems. The objective was to evaluate whether AI/LLM tools can (i) identify unique system states, (ii) compute dwell-time distributions, and (iii) derive state transition maps directly from raw CAN traces and DBC definitions. Additionally, we checked the possibility of these tools to analyze the quality of CAN communication (message cycle time). At the end of the study, we ran experiment tasks using CAN logs taken from a production car. Results show that AI-assisted analysis can extract operational states and transitions with varying levels of agreement with the deterministic baseline, supporting preparatory analysis during fuzzing test preparation. While performance varies across tools, AI support demonstrates strong potential for accelerating and assisting structured fuzz testing workflows.