Execution-Time Opacity Logic: A Logic for Ensuring ET-Opacity in Timed Systems

2026-09-09

AI Summary

为解决定时系统中执行时间导致的保密性问题，提出Execution-Time Opacity Logic(ETOL)，通过基于区域的模型检测框架有效验证执行时间保密性。

Abstract

Ensuring confidentiality in Cyber-Physical Systems is critical, especially when attackers exploit execution times to infer sensitiveinformation. Traditional opacity models are inadequate for timed systems, as verifying opacity in Timed Automata is undecidable. To address this challenge, we propose Execution-Time Opacity Logic (ETOL), a new formalism that specifies opacity by requiring that for every execution satisfying a secret formula, there exists another execution of the same duration that does not satisfy it. ETOL guarantees that timing observations cannot reveal confidential agent activities. We present a decidable and efficient verification framework based on zone-based model checking, supported by a dedicated algorithm that systematically identifies duration-equivalent executions. Our approach is validated through an ATM case study, showing that ETOL enables efficient verification of execution-time confidentiality under timing attacks. We also developed a prototype tool for the ETOL logic that supports symbolic model checking over timed systems. It allows users to verify ETOL formulas based on clock-constrained execution paths.

Problem

• Execution-Time Opacity
• Timed Systems
• Confidentiality
• Cyber-Physical Systems
• Timing Attacks

Innovation

• Execution-Time Opacity
• Timed Systems
• Zone-based Model Checking
• Symbolic Model Checking