Game-based verification of multi-party contract signing protocols

in Proceedings of 7th International Workshop on Formal Aspects in Security and Trust (FAST'09) (2010)

Game-Theoretic Foundations for Norms

in Procs. of Artificial Intelligence Studies (2006)

In this paper we study game-theoretic foundations for norms. We assume that a norm is a mechanism to obtain desired multi-agent system behavior, and must therefore under normal or typical circumstances be ... [more ▼]

In this paper we study game-theoretic foundations for norms. We assume that a norm is a mechanism to obtain desired multi-agent system behavior, and must therefore under normal or typical circumstances be fulfilled by a range of agent types, such as norm internalizing agents, respectful agents fulfilling norms if pos- sible, and selfish agents obeying norms only due to the associated sanctions. [less ▲]

Game-Theoretic Recruitment of Sensing Service Providers for Trustworthy Cloud-Centric Internet-of-Things (IoT) Applications

in IEEE Global Communications Conference (GLOBECOM) Workshops: Fifth International Workshop on Cloud Computing Systems, Networks, and Applications (CCSNA) (2016, December)

Widespread use of connected smart devices that are equipped with various built-in sensors has introduced the mobile crowdsensing concept to the IoT-driven information and communication applications ... [more ▼]

Widespread use of connected smart devices that are equipped with various built-in sensors has introduced the mobile crowdsensing concept to the IoT-driven information and communication applications. Mobile crowdsensing requires implicit collaboration between the crowdsourcer/recruiter platforms and users. Additionally, users need to be incentivized by the crowdsensing platform because each party aims to maximize their utility. Due to the participatory nature of data collection, trustworthiness and truthfulness pose a grand challenge in crowdsensing systems in the presence of malicious users, who either aim to manipulate sensed data or collaborate unfaithfully with the motivation of maximizing their income. In this paper, we propose a game-theoretic approach for trustworthiness-driven user recruitment in mobile crowdsensing systems that consists of three phases: i) user recruitment, ii) collaborative decision making on trust scores, and iii) badge rewarding. Our proposed framework incentivizes the users through a sub-game perfect equilibrium (SPE) and gamification techniques. Through simulations, we show that the platform utility can be improved by up to the order of 50\% while the average user utility can be increased by at least 15\% when compared to fully-distributed and user-centric trustworthy crowdsensing. [less ▲]

GAMES AND STRATEGIES IN ANALYSIS OF SECURITY PROPERTIES

Doctoral thesis (2016)

Information security problems typically involve decision makers who choose and adjust their behaviors in the interaction with each other in order to achieve their goals. Consequently, game theoretic ... [more ▼]

Information security problems typically involve decision makers who choose and adjust their behaviors in the interaction with each other in order to achieve their goals. Consequently, game theoretic models can potentially be a suitable tool for better understanding the challenges that the interaction of participants in information security scenarios bring about. In this dissertation, we employ models and concepts of game theory to study a number of subjects in the field of information security. In the first part, we take a game-theoretic approach to the matter of preventing coercion in elections. Our game models for the election involve an honest election authority that chooses between various protection methods with different levels of resistance and different implementation costs. By analysing these games, it turns out that the society is better off if the security policy is publicly announced, and the authorities commit to it. Our focus in the second part is on the property of noninterference in information flow security. Noninterference is a property that captures confidentiality of actions executed by a given process. However, the property is hard to guarantee in realistic scenarios. We show that the security of a system can be seen as an interplay between functionality requirements and the strategies adopted by users, and based on this we propose a weaker notion of noninterference, which we call strategic noninterference. We also give a characterisation of strategic noninterference through unwinding relations for specific subclasses of goals and for the simplified setting where a strategy is given as a parameter. In the third part, we study the security of information flow based on the consequences of information leakage to the adversary. Models of information flow security commonly prevent any information leakage, regardless of how grave or harmless the consequences the leakage can be. Even in models where each piece of information is classified as either sensitive or insensitive, the classification is “hardwired” and given as a parameter of the analysis, rather than derived from more fundamental features of the system. We suggest that information security is not a goal in itself, but rather a means of preventing potential attackers from compromising the correct behavior of the system. To formalize this, we first show how two information flows can be compared by looking at the adversary’s ability to harm the system. Then, we propose that the information flow in a system is effectively secure if it is as good as its idealized variant based on the classical notion of noninterference. Finally, we shift our focus to the strategic aspect of information security in voting procedures. We argue that the notions of receipt-freeness and coercion resistance are underpinned by existence (or nonexistence) of a suitable strategy for some participants of the voting process. In order toback the argument formally, we provide logical “transcriptions” of the informal intuitions behind coercion-related properties that can be found in the existing literature. The transcriptions are formulatedin the modal game logic ATL*, well known in the area of multi-agent systems. [less ▲]

Games for enhancing cognitive abilities

in Plass, Jan; Mayer, Richard E; Homer, Bruce D (Eds.) Handbook of Game-based Learning (2020)

Gamification of psychological tests: three lessons learned

in Testing International (2019), 42

Gaming concepts and incentives to change driver behaviour

in The 11th Annual Mediterranean Ad-Hoc Networking Workshop (2012)

In this paper we present a novel concept that deals specifically with changing driver behaviour in order to reduce traffic congestion. The project I-GEAR (incentives and gaming environments for automobile ... [more ▼]

In this paper we present a novel concept that deals specifically with changing driver behaviour in order to reduce traffic congestion. The project I-GEAR (incentives and gaming environments for automobile routing) aims to understand the motivations that drivers have while undertaking the daily commute and then to provide them with a range of incentives to change their behaviour. A key focus within the project is on ways in which the problem could potentially be solved without recourse to an expensive infrastructure project. Our solution to this problem was to move the problem of traffic management onto everyday mobile devices. In the following paper we outline the background to the problem, concepts relating to pervasive gaming, existing explorations of incentives and gaming approaches as well as our basic concept and project methodology. [less ▲]

The Gamma Stein equation and non-central de Jong theorems

in Bernoulli (in press)

GAN Applications with Discrete Data

Poster (2018, June 27)

GaN for THz Sources

in Proceedings of SPIE, vol. 7945, pp. 79450Y-1 - 79450Y-9 (2011)

In this work we investigate two different approaches to generate THz radiation by the use of the unique electrical and thermal properties of GaN. One method is heterodyne photomixing, a compact and ... [more ▼]

In this work we investigate two different approaches to generate THz radiation by the use of the unique electrical and thermal properties of GaN. One method is heterodyne photomixing, a compact and inexpensive approach to generate continuous electromagnetic radiation in the terahertz range, with tuneable frequency. It uses two lasers with slightly different wavelengths that illuminate an ultrafast photoconductor. The interference of both laser beams generates a beat frequency of the illumination intensity in the terahertz range. One drawback of the conventionally used LT GaAs as ultrafast photoconductor material is the relatively low THz power in the nW to ?W range. The aim of our work is to increase the output power by replacing the LT GaAs with GaN. This semiconductor is rather known as basic material for blue LEDs and lasers, but it has also remarkable electrical and thermal properties that allow higher laser power and bias voltage. A more conventional, electronic approach to generate THz radiation consists in the fabrication of an oscillator circuit based on ultrafast transistors, e.g. Hetero Field Effect Transistors based on InGaAs. These circuits can be designed up to about 100 GHz oscillation frequency. The THz region is achieved by frequency multipliers, e.g. realized by very small-sized Schottky diodes. However, each multiplier stage considerable reduces the output power. In this field we investigate GaN based transistor devices to profit from the much better power performance of this material, compared to classical semiconductors. Devices in this material system are usually used for high power applications at moderate frequencies, but the very high electron saturation velocity of GaN allows the application above 100 GHz as well. [less ▲]