AutoTrans: AI-Assisted Automatic Translation of Security Assertions for RISC-V Processors

Abstract

Reusing a set of verified security assertions across RISC-V processor targets remains one of the most expensive bottlenecks in hardware security verification. Manual translation takes hours per assertion. Raw LLM translation is fast but unreliable, introducing signal hallucination, where the model invents port names absent from the target RTL and produces outputs that may vary across model updates or even within the same model version. This paper presents AutoTrans, an automated framework that addresses the above shortcomings. First, a new lightweight Regular Expression-based System Verilog signal extractor is proposed to identify the signals for generating security assertions. This step is necessary to prevent signal hallucination. Second, a template is introduced to create prompt and pinned inference parameters that guarantee a byte-identical prompt assembly on every run, making the pipeline output resilient to model updates. Moreover, the introduced template for LLM prompting is capable of generating security assertions from English-only security descriptions of RISC-V processors, with no manual authoring. Third, a formal verification process (JasperGold FPV) is integrated, which guarantees that the generated security assertions verify the security of the RISC-V processor rather than silently entering the result set. The workflow is applied on Deepseek V4 to translate security assertions from one RISC-V to another (e.g., for IBEX from NS31A RISC-V). The experiment shows that AutoTrans achieves 78\% Auto Translation Acceptance Rate (TAR) automatically and without human intervention and 100\% Final TAR after refinement by humans.