Trust management has emerged as a promising technology to facilitate collaboration among entities in an environment where traditional security technologies cannot provide an effective solution. However, prior art generally lack considerations on usable means to gather and disseminate information for effective trust evaluation, as well as provide trust information to users in order to assist user decision. Current trust management solution could be hard to understand, use, and thus be accepted by the users. This chapter introduces a human-centric trust modeling and management method in order to design and develop a usable trust management solution that can be easily accepted by the users towards practical deployment. The authors illustrate how to apply this method into the design of a reputation system for mobile applications in order to demonstrate its effectiveness.
Top1. Introduction
Trust has two distinct characteristics. It is subjective, thus the level of trust considered sufficient is different for each individual in a certain situation. It is the subjective expectation of the trustor on the trustee that could influence the belief of the trustor. Trust is also dynamic as it is affected by many factors. It can further develop and evolve due to good experiences about the trustee. It is sensitive to be decayed caused by bad experiences.
Trust management has become a promising technology to facilitate collaboration among entities in a digital environment where traditional security technologies cannot provide an effective solution. Trust management is concerned with: collecting the information required to make a trust relationship decision; evaluating the criteria related to the trust relationship; monitoring and reevaluating existing trust relationships; as well as ensuring the dynamically changed trust relationships and automating the process (Grandison & Sloman, 2000; Yan & Prehofer, 2011). Various trust management systems have been described in the literature. One important category consists of reputation based trust management systems. Trust and reputation mechanisms have been proposed in various fields such as distributed computing, agent technology, GRID computing, and component software (Resnick & Zeckhauser, 2002; Xiong & Liu, 2004; Herrmann, 2001; Walsh & Sirer, 2005). Recently, many mechanisms have been developed for supporting trusted communications and collaborations among computing nodes in a distributed system (Sun, Yu, Han & Liu, 2006; Zhang, Wang & Wang, 2005; Theodorakopoulos & Baras, 2006; Lin, Varadharajan, Wang & Pruthi, 2004). These mechanisms are based on digital modeling of trust for trust evaluation and management.
Due to the subjective characteristic of trust, trust management needs to take the criteria of trustor into consideration. For a digital system, it is essential for the user device to understand the trust criteria of the user in order to behave as her/his agent for trust management. Generally, it is not good to require the user to make a lot of trust related decisions or interactions because that would destroy usability. Also, the user may not be informed enough to make sound decisions and act accordingly. Thus, establishing trust is quite a complicated task with many optional actions to take. Trust should rather be managed automatically following a high level policy established by the trustor (Yan & Prehofer, 2007; Yan & Prehofer, 2011). User-device interaction is needed if the device inquires trust criteria or feedback from the user in various contexts. This would require a friendly user interface to a) collect useful information for trust evaluation and management; b) present the evaluation results in a comprehensive and acceptable manner to the user; and c) disseminate individual experiences to other devices as recommendations or contribute to reputation generation. Or other novel approaches could be adopted to help us design a usable trust management system.
In this chapter, we introduce a human-centric trust modeling and management method in order to design and develop a usable trust management solution that can be easily accepted by the users towards practical deployment. Our focus is to manage trust between a user and a digital system, which is either a device or a digital system or service or a software application consumed by the user.
The rest of the chapter is organized as follows. Section 2 gives a brief overview of the literature background of social trust, computational trust and trust behavior studies. Section 3 introduces the method of human-centric trust modeling and management. In Section 4, we illustrate how to apply this method by taking the design and development of a reputation system for mobile applications as an example. We further discuss the advantages of our method in Section 5. Finally, conclusions and future work are presented in the last section.