CHERI Compartmentalisation for Embedded Systems
type: CreativeWork
description: Embedded system designers are facing an inexorable pressure to add more features and leverage connectivity. This creates potential attack vectors in areas that were not subject to security concerns before. Individuals’ privacy could be violated, cars and planes could crash, credit-card details could be stolen, and medical devices could critically malfunction, affecting vital life-concerning tasks or leaking sensitive patients’ details. Software compartmentalisation has the potential to manage the attack vector better, defend against unknown future software vulnerabilities, and limit the consequences of potential successful attacks to the compromised component without affecting the rest of the system. Unfortunately, the current state-of-the-art security technologies for embedded systems (e.g., MPUs) are not well-designed for implementing fine-grained software compartmentalisation while meeting embedded systems requirements. They suffer from inherent design issues that limit scalability, compatibility, security, and performance. This dissertation proposes CompartOS as a new lightweight hardware-software compartmentalisation model building on CHERI (a hardware capability architecture) to secure mainstream and complex embedded software systems. CompartOS is an automatic, linkage-based compartmentalisation model that isolates mutually distrusting linkage modules (e.g., third-party libraries) executing in a single-address-space and single-privilege-ring environment. Further, CompartOS enables the management of faults within software components by introducing support for partial recovery, thus improving availability while maintaining compatibility by requiring minimal development efforts—a critical requirement for many embedded systems. We have implemented multiple prototypes of compartmentalisation models, including MPU-based protection and CompartOS, in FreeRTOS and compared them in performance, compatibility, security, and availability. Microbenchmarks show that Compart…
abstract: Embedded system designers are facing an inexorable pressure to add more features and leverage connectivity. This creates potential attack vectors in areas that were not subject to security concerns before. Individuals’ privacy could be violated, cars and planes could crash, credit-card details could be stolen, and medical devices could critically malfunction, affecting vital life-concerning tasks or leaking sensitive patients’ details. Software compartmentalisation has the potential to manage the attack vector better, defend against unknown future software vulnerabilities, and limit the consequences of potential successful attacks to the compromised component without affecting the rest of the system. Unfortunately, the current state-of-the-art security technologies for embedded systems (e.g., MPUs) are not well-designed for implementing fine-grained software compartmentalisation while meeting embedded systems requirements. They suffer from inherent design issues that limit scalability, compatibility, security, and performance. This dissertation proposes CompartOS as a new lightweight hardware-software compartmentalisation model building on CHERI (a hardware capability architecture) to secure mainstream and complex embedded software systems. CompartOS is an automatic, linkage-based compartmentalisation model that isolates mutually distrusting linkage modules (e.g., third-party libraries) executing in a single-address-space and single-privilege-ring environment. Further, CompartOS enables the management of faults within software components by introducing support for partial recovery, thus improving availability while maintaining compatibility by requiring minimal development efforts—a critical requirement for many embedded systems. We have implemented multiple prototypes of compartmentalisation models, including MPU-based protection and CompartOS, in FreeRTOS and compared them in performance, compatibility, security, and availability. Microbenchmarks show that Compart…
author: Almatary, Hesham
language: eng
keywords: CHERI, compartmentalisation, embedded systems, security
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2022-02-23
date modified: 2026-07-22T22:23:56Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.88674