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Randomization as Mitigation of Directed Timing Inference Based Attacks on Time-Triggered Real-Time Systems with Task Replication

Krüger, Kristin ; Vreman, Nils LU ; Pates, Richard LU ; Maggio, Martina LU ; Völp, Marcus and Fohler, Gerhard (2021) In Leibniz Transactions on Embedded Systems
Abstract
Time-triggered real-time systems achieve deterministic behavior using schedules that are constructed offline, based on scheduling constraints. Their deterministic behavior makes time-triggered systems suitable for usage in safety-critical environments, like avionics. However, this determinism also allows attackers to fine-tune attacks that can be carried out after studying the behavior of the system through side channels, targeting safety-critical victim tasks. Replication -- i.e., the execution of task variants across different cores -- is inherently able to tolerate both accidental and malicious faults (i.e. attacks) as long as these faults are independent of one another. Yet, targeted attacks on the timing behavior of tasks which... (More)
Time-triggered real-time systems achieve deterministic behavior using schedules that are constructed offline, based on scheduling constraints. Their deterministic behavior makes time-triggered systems suitable for usage in safety-critical environments, like avionics. However, this determinism also allows attackers to fine-tune attacks that can be carried out after studying the behavior of the system through side channels, targeting safety-critical victim tasks. Replication -- i.e., the execution of task variants across different cores -- is inherently able to tolerate both accidental and malicious faults (i.e. attacks) as long as these faults are independent of one another. Yet, targeted attacks on the timing behavior of tasks which utilize information gained about the system behavior violate the fault independence assumption fault tolerance is based on. This violation may give attackers the opportunity to compromise all replicas simultaneously, in particular if they can mount the attack from already compromised components. In this paper, we analyze vulnerabilities of time-triggered systems, focusing on safety-certified multicore real-time systems. We introduce two runtime mitigation strategies to withstand directed timing inference based attacks: (i) schedule randomization at slot level, and (ii) randomization within a set of offline constructed schedules. We evaluate these mitigation strategies with synthetic experiments and a real case study to show their effectiveness and practicality. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Leibniz Transactions on Embedded Systems
ISSN
2199-2002
DOI
10.4230/LITES.7.1.1
project
Towards Adaptively Morphing Embedded Systems
Scalable Control of Interconnected Systems
language
English
LU publication?
yes
id
72274bdb-34c7-428c-a4a5-7a044ebfac4e
date added to LUP
2021-09-30 11:05:12
date last changed
2022-05-20 09:59:45
@article{72274bdb-34c7-428c-a4a5-7a044ebfac4e,
  abstract     = {{Time-triggered real-time systems achieve deterministic behavior using schedules that are constructed offline, based on scheduling constraints. Their deterministic behavior makes time-triggered systems suitable for usage in safety-critical environments, like avionics. However, this determinism also allows attackers to fine-tune attacks that can be carried out after studying the behavior of the system through side channels, targeting safety-critical victim tasks. Replication -- i.e., the execution of task variants across different cores -- is inherently able to tolerate both accidental and malicious faults (i.e. attacks) as long as these faults are independent of one another. Yet, targeted attacks on the timing behavior of tasks which utilize information gained about the system behavior violate the fault independence assumption fault tolerance is based on. This violation may give attackers the opportunity to compromise all replicas simultaneously, in particular if they can mount the attack from already compromised components. In this paper, we analyze vulnerabilities of time-triggered systems, focusing on safety-certified multicore real-time systems. We introduce two runtime mitigation strategies to withstand directed timing inference based attacks: (i) schedule randomization at slot level, and (ii) randomization within a set of offline constructed schedules. We evaluate these mitigation strategies with synthetic experiments and a real case study to show their effectiveness and practicality.}},
  author       = {{Krüger, Kristin and Vreman, Nils and Pates, Richard and Maggio, Martina and Völp, Marcus and Fohler, Gerhard}},
  issn         = {{2199-2002}},
  language     = {{eng}},
  month        = {{08}},
  series       = {{Leibniz Transactions on Embedded Systems}},
  title        = {{Randomization as Mitigation of Directed Timing Inference Based Attacks on Time-Triggered Real-Time Systems with Task Replication}},
  url          = {{http://dx.doi.org/10.4230/LITES.7.1.1}},
  doi          = {{10.4230/LITES.7.1.1}},
  year         = {{2021}},
}