In recent years, we have witnessed an increasing use of trust and reputation systems in different areas of ICT. The idea at the base of trust and reputation systems is of letting users to rate the provided services after each interaction. Other users may use aggregate ratings to compute reputation scores for a given party. The computed reputation scores are a collective measure of parties trust...

Reputation mechanisms for distributed e-Communities are vital tools for facilitating trust decisions regarding transactions between entities. Motivated by the current challenges in the area of P2P reputation systems regarding their desgign, credibilty enhancement and objective evaluation, in this thesis we worked towards (1) creating a framework for the development and evaluation of secure repu...

Cryptographic mechanisms alone are insufficient to protect Wireless Sensor Networks (WSNs), because sensors are deployed for long periods in hostile environments where it is possible for an adversary to physically take over a sensor and obtain access to the cryptographic keys stored in the sensor’s internal memory. Thus, reputation-based trust systems are employed to detect abnormal activities ...

Reputation systems can be used to foster good behaviour and to encourage adherence to contracts in e-commerce. Several reputation systems have been deployed in practical applications or proposed in the literature. This paper describes a new system called the beta reputation system which is based on using beta probability density functions to combine feedback and derive reputation ratings. The a...

Traditional approach of providing network security has been to borrow tools and mechanisms from cryptography. However, the conventional view of security based on cryptography alone is not sufficient for the defending against unique and novel types of misbehavior exhibited by nodes encountered in wireless communication networks. Reputation-based frameworks where nodes maintain reputation of othe...

Personal Network (PN) is a person-centric, distributed environment of a person’s devices that provides access to personal resources and services regardless the location of the person. A Federation of Personal Networks (Fednet) is a group-oriented network of PNs. A Fednet is a pervasive and ubiquitous computing technology that enables the users to enjoy cooperation and promises exciting opportun...

Iterated prisoner's dilemma (IPD) researchers have shown that strong positive reputations plus an efficient reputation evaluation system encourages both sides to pursue long-term collaboration and to avoid falling into mutual defection cycles. In agent-based environments with reliable reputation rating systems, agents interested in maximizing their private interests must show concern for other ...