Automatic RTL-to-Formal Code Converter for IP Security Formal Verification

Abstract

The wide usage of hardware intellectual property (IP) cores from untrusted vendors has raised security concerns in the integrated circuit (IC) industry. Existing testing methods are designed to validate the functionality of the hardware IP cores. These methods often fall short in detecting unspecified (often malicious) logic. Formal methods like Proof-Carrying Hardware (PCH), on the other hand, can help eliminate hardware Trojans and/or design backdoors by formally proving security properties on soft IP cores despite the high proof development cost. One of the causes to the high cost is the manual conversion of the hardware design from RTL code to a domain-specific language prior to verification. To mitigate this issue and to lower the overall cost of PCH framework, we propose an automatic code converter for translating VHDL to Formal-HDL, a domain specific language for representing hardware designs in Coq language. Our code converter provides support to wide variety of hardware designs. Towards the goal of speeding up the verification procedure in our PCH framework, the code converter is the important first step. The applicability of the tool is demonstrated by converting soft IP cores of AES to its Coq equivalent code.