DIALED: Data Integrity Attestation for Low-end Embedded Devices

TL;DR

DIALED introduces a novel data-flow attestation method for low-end embedded devices, enabling detection of data-only attacks with minimal overhead, complementing existing control-flow attestation techniques.

Contribution

It is the first data-flow attestation approach designed specifically for resource-constrained microcontrollers, enhancing security against data-only exploits.

Findings

Successfully detects data-only attacks on low-end MCUs.

Operates with low overhead suitable for resource-constrained devices.

Works alongside control-flow attestation for comprehensive security.

Abstract

Verifying integrity of software execution in low-end micro-controller units (MCUs) is a well-known open problem. The central challenge is how to securely detect software exploits with minimal overhead, since these MCUs are designed for low cost, low energy and small size. Some recent work yielded inexpensive hardware/software co-designs for remotely verifying code and execution integrity. In particular, a means of detecting unauthorized code modifications and control-flow attacks were proposed, referred to as Remote Attestation (RA) and Control-Flow Attestation (CFA), respectively. Despite this progress, detection of data-only attacks remains elusive. Such attacks exploit software vulnerabilities to corrupt intermediate computation results stored in data memory, changing neither the program code nor its control flow. Motivated by lack of any current techniques (for low-end MCUs) that detect these attacks, in this paper we propose, implement and evaluate DIALED, the first Data-Flow Attestation (DFA) technique applicable to the most resource-constrained embedded devices (e.g., TI MSP430). DIALED works in tandem with a companion CFA scheme to detect all (currently known) types of runtime software exploits at fairly low cost.