Human-Machine Trust Interaction

Improving user’s trust appropriately could help in designing an intelligent system and make it work effectively, especially with the fast growth of Web-base technology. This chapter introduces the solutions of improving user’s trust in human-machine interaction (HMI), especially for electronic commerce (e-commerce). The author firstly reviews the concept of trust and the main factors that affects the appropriateness of user’s trust in human-machine interaction, such as the properties of machine systems, the properties of human, and context. On the basis of these, the author further discusses the current state, challenges, problems and limitations of establishing and improving the user’s trust in human-machine interaction. Finally, the author summarizes and evaluates the existing solutions for improving the user’s trust appropriately in e-commerce environment.

Trust and Stability in Heterogeneous Multimedia Networks

In this chapter, the author views trust as the confidence in the association of a stable network execution to the efficient distribution of multimedia products in the final user. A network is stable under a greedy protocol (or a composition of protocols) if, for any adversary of injection rate less than 1, the number of packets in the network remains bounded at all times. The author focuses on a basic adversarial model for packet arrival and path determination for which the time-averaged arrival rate of packets requiring a single edge is no more than 1. Within this framework, the author studies the property of stability under various compositions of contention-resolution protocols and different packet trajectories trying to characterize this property in terms of network topologies. Furthermore, the author enhances the adversary allowing the monitoring of network link capacities/slowdowns. Within this context, the author shows how the stability properties of network topologies change when network link slowdowns/capacities can change dynamically. Interestingly, his results indicate that a composition of protocols leads to worst stability behaviour than having a single unstable protocol for contention-resolution. This suggests that the potential for instability incurred by the composition of protocols may be worse than that of some single protocol. Consequently, this study could help on the design and maintainance of trustworthy heterogeneous multimedia systems.

Rethinking Realistic Wireless Network Mobility

With recent advances of wireless ad hoc networking, especially opportunistic forwarding and cognitive radio, there is an increasing concern that existing mobility models are insufficient to represent network mobility in real world settings. In this chapter, the author discusses his proposal for a more realistic mobility model which captures key features of human movements in pervasive markets. His findings lead to a non-traditional mobility model which can be used to reconstruct the statistical patterns commonly observed in the literature, and facilitate the study of mobile communication and software engineering design problems under the context of pervasive computing for markets.

The Role of Trust in Social Life

This chapter reviews the literature of trust in sociology and psychology. By introducing the conception, theory model and measurement of trust, we discuss trust in three important social contexts: interpersonal situation, organizational settings and Internet life. Furthermore, the author proposes a synthetic trust model with a multi-disciplinary approach as a future research direction and described its implications for trust study.

Risk-Based Trust Management for E-Commerce

Electronic commerce (e-commerce) offers enormous opportunities for online trading while at the same time presenting potential risks. Although various mechanisms have been developed to elevate trust in e-commerce, research shows that shoppers continue to be skeptical about buying online and lack of trust is often cited as the main reason for it. Thus, enhancing success in e-commerce requires eliminating or reducing the risks. In this chapter, we present a multi-attribute trust management model that incorporates trust, transaction costs and product warranties. The new trust management system enables potential buyers to determine the risk level of a product before committing to proceed with the transaction. This is useful to online buyers as it allows them to be aware of the risk level and subsequently take the appropriate actions to minimize potential risks before engaging in risky businesses. Results of various simulation experiments show that the proposed multi-attribute trust management system can be highly effective in identifying risky transaction in electronic market places.

Formalizing and Managing Activity-Aware Trust in Collaborative Environments

Trust is an abstraction of individual beliefs that an entity has for specific situations and interactions. An entity’s beliefs are not static but they change as time progresses and new information is processed into knowledge. Trust must evolve in a consistent manner so that it still abstracts the entity’s beliefs accurately. In this way, an entity continuously makes informed decisions based on its current beliefs. This chapter presents and discusses a conceptual trust framework that models an entity’s trust as a relation whose state gets updated as relevant conditions that affect trust change. The model allows entities to reason about the specification and adaptation of trust that is placed in an entity. An intuitive and practical approach is proposed to manage end-to-end trust assessment for a particular activity, where multiple trust relationships are examined in a bottom-up evaluation manner to derive the overall trust for the activity.

A Context-Aware Model of Trust for Facilitating Secure Ad Hoc Collaborations

Ad hoc collaborations often necessitate impromptu sharing of sensitive information or resources between member organizations. Each member of resulting collaboration needs to carefully assess and tradeoff the requirements of protecting its own sensitive information against the requirements of sharing some or all of them. The challenge is that no policies have been previously arrived at for such secure sharing (since the collaboration has been formed in an ad hoc manner). Thus, it needs to be done based on an evaluation of the trustworthiness of the recipient of the information or resources. In this chapter, the authors discuss some previously proposed trust models to determine if they can be effectively used to compute trustworthiness for such sharing purposes in ad hoc collaborations. Unfortunately, none of these models appear to be completely satisfactory. Almost all of them fail to satisfy one or more of the following requirements: (i) well defined techniques and procedures to evaluate and/or measure trust relationships, (ii) techniques to compare and compose trust values which are needed in the formation of collaborations, and (iii) techniques to evaluate trust in the face of incomplete information. This prompts the authors to propose a new vector (we use the term “vector” loosely; vector in this work means a tuple) model of trust that is suitable for reasoning about the trustworthiness of systems built from the integration of multiple subsystems, such as ad hoc collaborations. They identify three parameters on which trust depends and formulate how to evaluate trust relationships. The trust relationship between a truster and a trustee is associated with a context and depends on the experience, knowledge, and recommendation that the truster has with respect to the trustee in the given context. The authors show how their model can measure trust in a given context. Sometimes enough information is not available about a given context to calculate the trust value. Towards this end the authors show how the relationships between different contexts can be captured using a context graph. Formalizing the relationships between contexts allows us to extrapolate values from related contexts to approximate a trust value of an entity even when all the information needed to calculate the trust value is not available. Finally, the authors develop formalisms to compare two trust relationships and to compose two or more of the same – features that are invaluable in ad hoc collaborations.

An Evaluation Framework for Reputation Management Systems*

Reputation management (RM) is employed in distributed and peer-to-peer networks to help users compute a measure of trust in other users based on initial belief, observed behavior, and run-time feedback. These trust values influence how, or with whom, a user will interact. Existing literature on RM focuses primarily on algorithm development, not comparative analysis. To remedy this, the authors propose an evaluation framework based on the trace-simulator paradigm. Trace file generation emulates a variety of network configurations, and particular attention is given to modeling malicious user behavior. Simulation is trace-based and incremental trust calculation techniques are developed to allow experimentation with networks of substantial size. The described framework is available as open source so that researchers can evaluate the effectiveness of other reputation management techniques and/or extend functionality. This chapter reports on the authors’ framework’s design decisions. Their goal being to build a general-purpose simulator, the authors have the opportunity to characterize the breadth of existing RM systems. Further, they demonstrate their tool using two reputation algorithms (EigenTrust and a modified TNA-SL) under varied network conditions. The authors’ analysis permits them to make claims about the algorithms’ comparative merits. They conclude that such systems, assuming their distribution is secure, are highly effective at managing trust, even against adversarial collectives.

Trust Management for Grid Systems

Grid computing is a paradigm for distributed computation on shared resources. It uses a large-scale, highly decentralized infrastructure, in which a huge number of participants share heterogeneous resources for a given purpose. Each participant both provides their own resources and exploits others’ resources, combining them to solve their own problems. Trust management is a major issue in the shared Grid environment because Grid participants are usually unknown to each other and usually belong to separate administrative domains, with little or no common trust in the security of opposite infrastructures. The standard security support provided by the most common Grid middleware may be regarded as one means through which such common trust may be established. However, such security solutions are insufficient to exhaustively address all the trust requirements of Grid environments. In this chapter, the authors survey proposals for enhancing trust management in Grid systems.

Certificate-Based Trust Establishment in eEnabled Airplane Applications

This chapter describes potential roles of trust in future aviation information systems. The next-generation air transportation systems are envisioned to be a highly networked environment with aircraft digitally linked with ground systems and wireless technologies allowing real-time continuous sensing, collection and distribution of aircraft information assets. The resulting enhancements promise to revolutionize manufacturing, operation and maintenance of commercial airplanes. Safe and dependable aircraft operation as well as public well-being in these complex system-of-systems with multiple stakeholders, demands that the distributed information assets can be trusted to be correct and that the level of trustworthiness in systems can be established. This chapter considers two recent abstractions of such aviation systems – an electronic distribution system connecting aircraft with ground components for exchanging updates and data of onboard software, and a radio frequency identification (RFID) system for logistics and maintenance of aircraft – which use digital certificates to establish trust in integrity and authenticity of information assets as well as in authorized components handling these assets. The chapter presents unique challenges of aviation, such as regulations and business models, which can complicate implementation of certificate-based trust and further warrant trustworthiness proofs.