arXiv subjects
Publications and source records attributed to Sjouke Mauw.
The present volume contains the proceedings of the Fourth International Workshop on Engineering Safety and Security Systems (ESSS'15). The workshop was held in Oslo, Norway, on June 22nd, 2015, as a satellite event of the 20th International Symposium on Formal Methods (FM'15).
Distance bounding protocols are security countermeasures designed to thwart relay attacks. Such attacks consist in relaying messages exchanged between two parties, making them believe they communicate directly with each other. Although distance bounding protocols have existed since the early nineties, this research topic resurrected with the deployment of contactless systems, against which relay attacks are particularly impactful. Given the impressive number of distance bounding protocols that are designed every year, it becomes urgent to provide researchers and engineers with a methodology to fairly compare the protocols in spite of their various properties. This paper introduces such a methodology based on concepts from the decision making field. The methodology allows for a multi-criteria comparison of distance bounding protocols, thereby identifying the most appropriate protocols once the context is provided. As a side effect, this paper clearly identifies the protocols that should no longer be considered, regardless of the considered scenario.
We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND attack tree formalism increases the expressivity of attack trees by introducing the sequential conjunctive operator SAND. This operator enables the modeling of ordered events. We give a semantics to SAND attack trees by interpreting them as sets of series-parallel graphs and propose a complete axiomatization of this semantics. We define normal forms for SAND attack trees and a term rewriting system which allows identification of semantically equivalent trees. Finally, we formalize how to quantitatively analyze SAND attack trees using attributes.
Multi-party contract signing (MPCS) protocols allow a group of signers to exchange signatures on a predefined contract. Previous approaches considered either completely linear protocols or fully parallel broadcasting protocols. We introduce the new class of DAG MPCS protocols which combines parallel and linear execution and allows for parallelism even within a signer role. This generalization is useful in practical applications where the set of signers has a hierarchical structure, such as chaining of service level agreements and subcontracting. Our novel DAG MPCS protocols are represented by directed acyclic graphs and equipped with a labeled transition system semantics. We define the notion of abort-chaining sequences and prove that a DAG MPCS protocol satisfies fairness if and only if it does not have an abort-chaining sequence. We exhibit several examples of optimistic fair DAG MPCS protocols. The fairness of these protocols follows from our theory and has additionally been verified with our automated tool. We define two complexity measures for DAG MPCS protocols, related to execution time and total number of messages exchanged. We prove lower bounds for fair DAG MPCS protocols in terms of these measures.
The present volume contains the proceedings of the First International Workshop on Graphical Models for Security (GraMSec'14). The workshop was held in Grenoble, France, on April 12, 2014, as one of the satellite events of the European Joint Conferences on Theory and Practice of Software 2014 (ETAPS'14). Graphical security models provide an intuitive but systematic methodology to analyze security weaknesses of systems and to evaluate potential protection measures. Such models have been subject of academic research and they have also been widely accepted by the industrial sector, as a means to support and facilitate threat analysis and risk management processes. The objective of GraMSec is to contribute to the development of well-founded graphical security models, efficient algorithms for their analysis, as well as methodologies for their practical usage. The workshop brings together academic researchers and industry practitioners designing and employing visual models for security in order to provide a platform for discussion, knowledge exchange and collaborations.
The ADTool is free, open source software assisting graphical modeling and quantitative analysis of security, using attack-defense trees. The main features of the ADTool are easy creation, efficient editing, and automated bottom-up evaluation of security-relevant measures. The tool also supports the usage of attack trees, protection trees and defense trees, which are all particular instances of attack-defense trees.
Attack-defense trees are a novel methodology for graphical security modeling and assessment. The methodology includes visual, intuitive tree models whose analysis is supported by a rigorous mathematical formalism. Both, the intuitive and the formal components of the approach can be used for quantitative analysis of attack-defense scenarios. In practice, we use intuitive questions to ask about aspects of scenarios we are interested in. Formally, a computational procedure, defined with the help of attribute domains and a bottom-up algorithm, is applied to derive the corresponding numerical values. This paper bridges the gap between the intuitive and the formal way of quantitatively assessing attack-defense scenarios. We discuss how to properly specify a question, so that it can be answered unambiguously. Given a well specified question, we then show how to derive an appropriate attribute domain which constitutes the corresponding formal model. Since any attack tree is in particular an attack-defense tree, our analysis is also an advancement of the attack tree methodology.
In this paper, we apply the probabilistic model checker PRISM to the analysis of a biological system -- the Platelet-Derived Growth Factor (PDGF) signaling pathway, demonstrating in detail how this pathway can be analyzed in PRISM. We show that quantitative verification can yield a better understanding of the PDGF signaling pathway.
With the prevalence and development of GNSS technologies, location-based vehicle services (LBVS) have experienced a rapid growth in recent years. However, location is a sensitive and private piece of information, so the design and development of such services just take the clients' privacy concerns into account. In this paper, we propose a new electronic toll pricing system based on group signatures, which provides a strong guarantee for the clients' anonymity within groups. Our system achieves a balance between privacy and the communication overhead imposed upon the users.
Attack--defense trees are used to describe security weaknesses of a system and possible countermeasures. In this paper, the connection between attack--defense trees and game theory is made explicit. We show that attack--defense trees and binary zero-sum two-player extensive form games have equivalent expressive power when considering satisfiability, in the sense that they can be converted into each other while preserving their outcome and their internal structure.
Automatic security protocol analysis is currently feasible only for small protocols. Since larger protocols quite often are composed of many small protocols, compositional analysis is an attractive, but non-trivial approach. We have developed a framework for compositional analysis of a large class of security protocols. The framework is intended to facilitate automatic as well as manual verification of large structured security protocols. Our approach is to verify properties of component protocols in a multi-protocol environment, then deduce properties about the composed protocol. To reduce the complexity of multi-protocol verification, we introduce a notion of protocol independence and prove a number of theorems that enable analysis of independent component protocols in isolation. To illustrate the applicability of our framework to real-world protocols, we study a key establishment sequence in WiMax consisting of three subprotocols. Except for a small amount of trivial reasoning, the analysis is done using automatic tools.