SoK: Analysis of Root Causes and Defense Strategies for Attacks on Microarchitectural Optimizations

TL;DR

This paper systematically analyzes timing-based side-channel attacks on microarchitectural optimizations, identifying root causes and evaluating defense strategies to enhance security without compromising performance.

Contribution

It introduces a framework for analyzing attacks and defenses, identifying four root causes of side-channel vulnerabilities, and systematizing existing defenses targeting these causes.

Findings

Four root causes of timing attacks identified: determinism, sharing, access violation, information flow.

Existing defenses are mapped to these root causes and attack steps.

A systematic approach to analyzing and defending against microarchitectural timing attacks.

Abstract

Microarchitectural optimizations are expected to play a crucial role in ensuring performance scalability in future technology nodes. However, recent attacks have demonstrated that microarchitectural optimizations, which were assumed to be secure, can be exploited. Moreover, new attacks surface at a rapid pace limiting the scope of existing defenses. These developments prompt the need to review microarchitectural optimizations with an emphasis on security, understand the attack landscape and the potential defense strategies. We analyze timing-based side-channel attacks targeting a diverse set of microarchitectural optimizations. We provide a framework for analysing non-transient and transient attacks, which highlights the similarities. We identify the four root causes of timing-based side-channel attacks: determinism, sharing, access violation and information flow, through our systematic analysis. Our key insight is that a subset (or all) of the root causes are exploited by attacks and eliminating any of the exploited root causes, in any attack step, is enough to provide protection. Leveraging our framework, we systematize existing defenses and show that they target these root causes in the different attack steps.