Carlos Ballester Lafuente

Flexible Communication: A Secure and Trust-Based Free Wi-Fi Password Sharing Service

During the last few years the amount of users with mobile devices (laptops, smart phones, tablets, etc.) with wireless connectivity capabilities has grown at an impressive rate. In the meantime, the number of Wi-Fi networks has also increased a lot, and in addition to this, the emergence and fast growth of applications such as social networking, user generated content, location services, collaborative tools and applications, etc. has fueled the users need for permanent connectivity. This paper introduces Flexible Communication, a secure and trust-based Wi-Fi password sharing service. Our service architecture provides the user with a solution that enables free Wi-Fi network password sharing, which relies on a social-networking oriented trust model approach and which at the same time allows the user to locate and to connect to those Wi-Fi networks at any time. We validate our solution with a qualitative assessment which compares its features against those of the other similar existent solutions and also with a quantitative assessment which measures the performance both of the server and the client.

Trust Management in ULOOP

This White Paper provides an insight on Trust Management within the context of the User-centric Wireless Local Loop (ULOOP) project, depicting the main principles and the overall trust management framework, and also describing its main individual components. It has as motivation to disseminate ULOOP concepts and to raise awareness towards trust management in user-centric wireless networks.

Dispositional Trust Adaptation in User-Centric Networks

Wireless networks today are partially being formed by nodes (e.g. Internet access points, smartphones, femtocells)that are owned and carried by humans. In such scenarios where several strangers are expected to interact for the sake of robust data transmission, trust and reputation are of vital importance. As such, User Centric Networks require well-defined trust metrics in order to ensure the robustness and reliability of the overall system. Dispositional Trust (DT) is defined as the general willingness of a given user/entity to trust others and it is used in many trust metrics as part of the threshold under which an entity will not trust another. In this paper we propose that dispositional trust should not be a static value and that it should change and self-adapt depending on the surrounding environment and context, in order for the overall trust metric to be more robust and to be able to converge faster to realistic trust measurements regarding the other surrounding entities in the system. To prove our statement, we compare other trust metrics with the one we propose in a simulated environment, in order to quantitatively assess whether our dispositional trust self-adaptation makes a difference in the robustness of the metric while maintaining when possible the network utility.

Design and validation of a trust-based opportunity-enabled risk management system

Purpose The Bring-Your-Own-Device (BYOD) paradigm favors the use of personal and public devices and communication means in corporate environments, thus representing a challenge for the traditional security and risk management systems. In this dynamic and heterogeneous setting, the purpose of this paper is to present a methodology called opportunity-enabled risk management (OPPRIM), which supports the decision-making process in access control to remote corporate assets. Design/methodology/approach OPPRIM relies on a logic-based risk policy model combining estimations of trust, threats and opportunities. Moreover, it is based on a mobile client – server architecture, where the OPPRIM application running on the user device interacts with the company IT security server to manage every access request to corporate assets. Findings As a mandatory requirement in the highly flexible BYOD setting, in the OPPRIM approach, mobile device security risks are identified automatically and dynamically depending on the specific environment in which the access request is issued and on the previous history of events. Originality/value The main novelty of the OPPRIM approach is the combined treatment of threats (resp., opportunities) and costs (resp., benefits) in a trust-based setting. The OPPRIM system is validated with respect to an economic perspective: cost-benefit sensitivity analysis is conducted through formal methods using the PRISM model checker and through agent-based simulations using the Anylogic framework.

Extending trust management with cooperation incentives: a fully decentralized framework for user-centric network environments

While trust management systems can be used in isolation in order to provide robustness to a given architecture, cooperation incentives can be used to complement and collaborate with trust management systems as users can benefit from them while using the system, thus encouraging user’s good behaviour. We have designed a fully decentralized trust management and cooperation incentives framework for user-centric network environments composed by three main components, the identity manager, the trust manager and the cooperation manager. In this article, we present how we integrate our trust management and cooperation incentives framework with a collaborative wireless access sharing service, being the aim of the article to evaluate its feasibility from a bootstrapping and survivability point of view. Our results obtained through simulation prove that the values for bootstrapping and data depletion times are well inside acceptable ranges, given that the total user base for the framework in the world is big enough while using friend-of-a-friend chains.

Extending Trust Management with Cooperation Incentives: Achieving Collaborative Wi-Fi Sharing Using Trust Transfer to Stimulate Cooperative Behaviours

There are still many issues to achieve collaborative Wi-Fi sharing: the legal liability of the sharer; high data access costs in some situations (mobility when going over a monthly subscription quota, roaming…); no appropriate incentives to share. Current trust management could exclude the malicious users, but still could not foster Wi-Fi sharing. We have extended an appropriate trust metric with cooperation incentives to mitigate all the above issues. We have evaluated our proposal with a trust metric and incentive effectiveness through simulations and we have found the bootstrapping time for such a system and the average depletion time for its users linking it with the size of the system’s user base, proving the feasibility for such a combination.

Secure user-friendly Wi-Fi access point joining

In this paper, we discuss the remaining security risk of Wi-Fi AP spoofing with current AP joining approaches and how a new solution has been developed as part of the ULOOP project in order to be more user-friendly and secure. It was an important step for increased security because our evaluation shows that even computer aware users do not know or do not bother about this issue although it is a real risk that current approaches do not solve.

Crowd augmented wireless access

Environments such as ski slopes are highly dynamic, as users are constantly moving at high speeds and in different directions, and also many users are not locals, thus having to roam in order to be able to connect through mobile data. These two previous reasons make connectivity through regular means to be difficult to attain. This demo paper presents the simulation and validation of a crowd augmented wireless access used in order to tackle this problem.

On the Tradeoff among Trust, Privacy, and Cost in Incentive-Based Networks

Incentive strategies are used in collaborative user-centric networks, the functioning of which depends on the willingness of users to cooperate. Classical mechanisms stimulating cooperation are based on trust, which allows to set up a reputation infrastructure quantifying the subjective reliance on the expected behavior of users, and on virtual currency, which allows to monetize the effect of prosocial behaviors. In this paper, we emphasize that a successful combination of social and economic strategies should take into account the privacy of users. To this aim, we discuss the theoretical and practical issues of two alternative tradeoff models that, depending on the way in which privacy is disclosed, reveal the relation existing among trust, privacy, and cost.