Bounded opacity for timed systems

Ammar, Ikhlass; Touati, Yamen El; Yeddes, Moez; Mullins, John

doi:10.1016/j.jisa.2021.102926

Cited by 13 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[WZA18] allows to check language-opacity on real-time automata, made possible by the strong syntactic restrictions on this subclass of TAs, while [Amm+21] allows to check location-based language opacity (over bounded time) on non-Zeno timed automata. [VNN18] allows to check non-interference on variable flow on TAs.…”

Section: Discussionmentioning

confidence: 99%

“…A recent work by Ammar et al [Amm+21] addresses the timed opacity problem in a similar fashion to [Cas09]: an intruder has access to a subset of actions, along with timed information. The originality of [Amm+21] is to consider a time-bounded…”

Section: Timed Opacitymentioning

confidence: 99%

“…The problem can then be solved by the timed bounded inclusion checking, which is decidable for timed automata [ORW09]; this is in contrast with the (potentially unbounded) language inclusion checking, known to be undecidable [AD94]. This time-bounded setting is the crux that explains the difference of decidability between [Cas09] and [Amm+21]. A case study on a cloud service model illustrates the method by determining the δ value up to which the system is δ-duration bounded opaque.…”

Section: Timed Opacitymentioning

confidence: 99%

“…Example 11. Here, we illustrate the δ-duration bounded opacity from [Amm+21]. Consider the TA in Fig.…”

Section: Timed Opacitymentioning

confidence: 99%

See 3 more Smart Citations

Timed Automata as a Formalism for Expressing Security: A Survey on Theory and Practice

Arcile

André

2022

ACM Comput. Surv.

View full text Add to dashboard Cite

Timed automata are a common formalism for the verification of concurrent systems subject to timing constraints. They extend finite-state automata with clocks, that constrain the system behavior in locations, and to take transitions. While timed automata were originally designed for safety (in the wide sense of correctness w.r.t. a formal property), they were progressively used in a number of works to guarantee security properties. In this work, we review works studying security properties for timed automata in the last two decades. We notably review theoretical works, with a particular focus on opacity, as well as more practical works, with a particular focus on attack trees and their extensions. We derive main conclusions concerning open perspectives, as well as tool support.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Timed Opacitymentioning

confidence: 99%

Section: Timed Opacitymentioning

confidence: 99%

“…Example 11. Here, we illustrate the δ-duration bounded opacity from [Amm+21]. Consider the TA in Fig.…”

Section: Timed Opacitymentioning

confidence: 99%

See 2 more Smart Citations

Timed Automata as a Formalism for Expressing Security: A Survey on Theory and Practice

Arcile

André

2022

ACM Comput. Surv.

View full text Add to dashboard Cite

show abstract

“…In [Amm+21], the authors consider a time-bound opacity, where the attacker has to disclose the secret before an upper bound, using a partial observability. The authors prove that this problem is decidable for TAs.…”

Section: Contributions For Parametric Tasmentioning

confidence: 99%

Guaranteeing Timed Opacity using Parametric Timed Model Checking

André,

Lime,

Marinho

et al. 2022

Preprint

View full text Add to dashboard Cite

Information leakage can have dramatic consequences on systems security. Among harmful information leaks, the timing information leakage occurs whenever an attacker successfully deduces confidential internal information. In this work, we consider that the attacker has access (only) to the system execution time. We address the following timed opacity problem: given a timed system, a private location and a final location, synthesize the execution times from the initial location to the final location for which one cannot deduce whether the system went through the private location. We also consider the full timed opacity problem, asking whether the system is opaque for all execution times. We show that these problems are decidable for timed automata (TAs) but become undecidable when one adds parameters, yielding parametric timed automata (PTAs). We identify a subclass with some decidability results. We then devise an algorithm for synthesizing PTAs parameter valuations guaranteeing that the resulting TA is opaque. We finally show that our method can also apply to program analysis.

show abstract