Trust Nothing: RTOS Security without Run-Time Software TCB (Extended Version)

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Ackermann, Eric, Bugiel, Sven
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866910046406836224
author Ackermann, Eric
Bugiel, Sven
author_facet Ackermann, Eric
Bugiel, Sven
contents Embedded devices face an ever-expanding threat landscape: vulnerabilities in application software, operating system kernels, and peripherals threaten the embedded device integrity. Existing computer-architectural defenses fully consider at most two of these threat vectors in their security model. This paper aims at addressing this gap using a novel capability architecture. To this end, we combine a token capability approach suitable for building an untrusted operating system with protection against malicious devices without requiring hardware changes to peripherals. First, we develop and evaluate a full FPGA implementation of our capability architecture around legacy hardware components. Further, we present a soft real-time operating system based on Zephyr that has no run-time software TCB. To this end, we disaggregate Zephyr's subsystems into small, mutually isolated components. All subsystems that exist at run time, including scheduler, allocator and DMA drivers, and all peripherals are fully untrusted. We believe that our work offers a foundation for more rigorous security-by-design in tomorrow's security-critical embedded devices.
format Preprint
id arxiv_https___arxiv_org_abs_2603_08400
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Trust Nothing: RTOS Security without Run-Time Software TCB (Extended Version)
Ackermann, Eric
Bugiel, Sven
Cryptography and Security
Hardware Architecture
Operating Systems
B.4.3; D.4.6
Embedded devices face an ever-expanding threat landscape: vulnerabilities in application software, operating system kernels, and peripherals threaten the embedded device integrity. Existing computer-architectural defenses fully consider at most two of these threat vectors in their security model. This paper aims at addressing this gap using a novel capability architecture. To this end, we combine a token capability approach suitable for building an untrusted operating system with protection against malicious devices without requiring hardware changes to peripherals. First, we develop and evaluate a full FPGA implementation of our capability architecture around legacy hardware components. Further, we present a soft real-time operating system based on Zephyr that has no run-time software TCB. To this end, we disaggregate Zephyr's subsystems into small, mutually isolated components. All subsystems that exist at run time, including scheduler, allocator and DMA drivers, and all peripherals are fully untrusted. We believe that our work offers a foundation for more rigorous security-by-design in tomorrow's security-critical embedded devices.
title Trust Nothing: RTOS Security without Run-Time Software TCB (Extended Version)
topic Cryptography and Security
Hardware Architecture
Operating Systems
B.4.3; D.4.6
url https://arxiv.org/abs/2603.08400