Silke Holtmanns

Context-Aware Adaptive Trust

Trust is a very complex and multi-disciplined concept. In this article we start by analysing social trust scenarios to derive abstract trust concepts. From these abstract trust concepts a context-aware adaptive trust concept is developed. The context aware adaptive trust concept takes into account the dynamics of trust and the context based grouping of trust properties. The implementation of the concept will be subject to further evaluation and research.

Tailored trustworthiness estimations in Peer-to-Peer networks

In peer-to-peer (P2P) communities, users make personal trust evaluations of each other based on their experiences and observations. The available information of the peers past behavior, i.e. reputation, is often incomplete, the credibility of evaluations is a concern and the relevance of the available information varies. In this paper, we propose functions for producing tailored trustworthiness estimations in P2P communities based on the peers past behavior. The presented mechanism provides some flexibility on applying it in different kinds of P2P networks.

Tailored trustworthiness estimations in peer-to-peer networks

In peer-to-peer (P2P) communities, users make personal trust evaluations of each other based on their experiences and observations. The available information of the peers past behavior, i.e. reputation, is often incomplete, the credibility of evaluations is a concern and the relevance of the available information varies. In this paper, we propose functions for producing tailored trustworthiness estimations in P2P communities based on the peers past behavior. The presented mechanism provides some flexibility on applying it in different kinds of P2P networks.

A Formal Approach to Identifying Security Vulnerabilities in Telecommunication Networks

The number of security attacks on the telecommunication networks is constantly increasing. To prevent them, the telecom sector is looking for new automated techniques facilitating a discovery of potential network vulnerabilities and rectification of them. In this paper, we propose an approach for identifying potential attack scenarios and defining recommendations for preventing them. The approach is formalised in the Event-B framework. It allows us to not only formalise the analysed part of the network architecture and verify consistency of the control and data flow of the associated services but also employ model checking to generate and analyse attack scenarios. By applying the proposed approach, the designers can systematically explore network vulnerabilities and propose recommendations for attack prevention.

Access Authentication to IMS Systems in Next Generation Networks

IP multimedia system (IMS) access authentication over fixed networks faces some challenges in the process of converging fixed and mobile networks. Authentication in 3GPP IMS system is bound to lower layer authentication mechanisms, hence the used protocols can not be used directly for the NGN fixed network environment. Therefore different mechanisms were proposed in standardization, we will outline the approaches and their integration into the 3GPP IMS system.