Design and formal analysis of a group signature based electronic toll pricing system

in Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications (2013), 4(1), 55-75

Implementation and Validation of a Localisation Assurance Service Provider

in Proc. 6th ESA Workshop on Satellite Navigation Technologies (2012)

Existing Global Navigation Satellite Systems offer no authentication to the open service signals and so stand-alone receivers are vulnerable to meaconing and spoofing attacks. These attacks interfere with ... [more ▼]

Existing Global Navigation Satellite Systems offer no authentication to the open service signals and so stand-alone receivers are vulnerable to meaconing and spoofing attacks. These attacks interfere with the integrity and authenticity of satellite signals: they can delay signals, or re-broadcast signals. Positioning is thus compromised and location-based services are at risk.This paper describes a solution to mitigate this risk. It is a trusted third-party Localisation Assurance service that informs location-based services providers up to which level a location claimed by client can be trusted. It runs several tests over the localisation data of client receivers and certifies the level of assurance of locations. An assurance level expresses the amount of trust the third-party has that a receiver's location is calculated from integral and authentic satellite signals. [less ▲]

Input online review data and related bias in recommender systems

in Decision Support Systems (2012), 53(3), 418-424

A majority of extant literature on recommender systems assume the input data as a given to generate recommendations. Both implicit and/or explicit data are used as input in these systems. The existence of ... [more ▼]

A majority of extant literature on recommender systems assume the input data as a given to generate recommendations. Both implicit and/or explicit data are used as input in these systems. The existence of various challenges in using such input data including those associated with strategic source manipulations, sparse matrix, state data, among others, are sometimes acknowledged. While such input data are also known to be rife with various forms of bias, to our knowledge no explicit attempt is made to correct or compensate for them in recommender systems. We consider a specific type of bias that is introduced in online product reviews due to the sequence in which these reviews are written. We model several scenarios in this context and study their properties. [less ▲]

Fairness in Non-repudiation Protocols

in Proceedings of STM 2011 (2012)

A group signature based electronic toll pricing system

in Proc. 7th International Conference on Availability, Reliability and Security (2012)

Game-based verification of contract signing protocols with minimal messages

in Innovations in Systems and Software Engineering (2012), 8

Detecting meaconing attacks by analysing the clock bias of GNSS receivers

in European Navigation Conference (ENC 2012) (2012)

Existing Global Navigation Satellite Systems offer no authentication of their satellite signals towards their civilian users. As a consequence, several types of GNSS-related attacks, including meaconing ... [more ▼]

Existing Global Navigation Satellite Systems offer no authentication of their satellite signals towards their civilian users. As a consequence, several types of GNSS-related attacks, including meaconing, may be performed and remain undetected. In the scope of the project “Developing a prototype of Localisation Assurance Service Provider”, which is funded by ESA and realised by the company itrust consulting and the University of Luxembourg, a methodology to visualise the beginnings and the ends of meaconing attacks by monitoring the clock bias of an attacked receiver over time was developed. This paper presents an algorithm that is based on this attack visualisation technique and is capable of detecting meaconing attacks automatically. Experiments in a controlled environment confirmed that the chosen methodology works properly. In one of these tests, for example, six meaconing attacks were simulated by using a GNSS signal repeater. The algorithm was able to detect the beginnings and the ends of all six attacks, while resulting in no more than two false positives, even though the average delay introduced by the meaconing stations (repeater) was just 80 nanoseconds. [less ▲]

Quantitative Questions on Attack-Defense Trees

in Information Security and Cryptology - ICISC 2012 - 15th International Conference, Seoul, Korea, November 28-30, 2012, Revised Selected Papers (2012)

Attack-defense trees are a novel methodology for graphical security modeling and assessment. The methodology includes intuitive and formal components that can be used for quantitative analysis of attack ... [more ▼]

Attack-defense trees are a novel methodology for graphical security modeling and assessment. The methodology includes intuitive and formal components that 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, using 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. [less ▲]

mCarve: Carving attributed dump sets

in Abstract book of 20th USENIX Security Symposium (2011)

A study of the PDGF signaling pathway with PRISM

in Proceedings of the 3rd Workshop on Computational Models for Cell Processes (2011), EPTCS 67