A Formal Framework for Gate- Level Information Leakage Using Z3

Abstract

Ahstract- The hardware intellectual property (IP) cores from untrusted vendors are widely used, which has raised security concerns for system designers. Although formal methods provide powerful solutions for detecting malicious behaviors in hardware, the participation of manual work prevents the methods from practical applications. Information Flow Tracking (IFT) is a powerful approach to prevent sensitive information leakage. However, existing IFT solutions are either introducing overhead in hardware or lacking practical automatic working procedures. To alleviate these challenges, we propose a framework that fully automates information leakage detection in the gate level of hardware. This framework introduces Z3, an SMT solver, in checking the violation of the confidentiality automatically. On the other hand, a parser converting the gate-level hardware to the formal model is developed to further remove the manual workload. To validate the effectiveness, the proposed solution is tested on 11 gate-level netlist benchmarks. The Trojans leaking information from circuit outputs can be automatically detected. We also account for time consumption during the whole working procedure to show the efficiency of the proposed approach.