A Formal Methodology for Verifying Side-Channel Vulnerabilities in Cache Architectures

Abstract

Security-aware CPU caches have been designed to mitigate side-channel attacks and prevent information leakage. How to validate the effectiveness of these designs remains an unsolved problem. Prior works assess the security of architectures empirically without a formal guarantee, making the evaluation results less convincing. In this paper, we propose a comprehensive methodology based on formal methods for security verification of cache architectures. Specifically, we design an entropy-based noninterference reasoning framework with two unwinding conditions to assess the information leakage of the cache designs. The reasoning framework quantifies the dependency relationships by the mutual information between the distributions of input and output of side channels. Given a cache design, we formalize its behavior specification along with the cache layouts into an abstract state machine, to instantiate the parameterized reasoning framework that discloses any potential vulnerabilities. We use our methodology to assess eight state-of-the-art cache architectures to demonstrate reliability as well as flexibility.

Securing smart contracts with formal verification and automated program repair

“…An established way to rigorously verify correctness of safety-critical systems, including smart contracts, is to employ formal verification, i.e., use various mathematical methods to prove or disprove safety and correctness of the code or its model based on a given specification [156,148]. On December 3, 2022, the query "smart contract verification" on Google Scholar generated 17200 results published since 2018.…”

“…High risks associated with the usage of smart contracts require obtaining security guarantees that are appropriate for a safety-critical system. A well-established method for rigorously verifying the correctness of a safety-critical system, such as a smart contract, is formal verification [316,156,148].…”