Trust* : Extending the Reach of Trust in Distributed Systems
Building trust is a common requirement in distributed environments especially since many transactions now occur on a person-to-person basis. Examples range from e-commerce on the Internet to peer-to-peer and grid resource sharing. Many solutions to the problem of requiring trust among unknown entities rely on the use of a reputation metric to assess the risk of a potential transaction. However, such reputation systems require (often implicitly) that trust is transitive which can be a problematic assumption. This dissertation proposes a novel mechanism which we call trust*. The trust* model uses guarantees to extend local trust between unknown end-points. Trust* can be used as a substitution for end-to-end trust. Principals provide guarantees within existing (local) trust relationships to build a chain of localised agreements between the unknown end-points. The guarantees are backed by local micropayments to provide deterrents and incentives. Trust* relationships can be composed transitively, and the guarantees reduce the risk for the trusting party when doing so. This is because a guarantee is only ever provided locally by a directly trusted principal. Thus, trust management can be reduced to a locally solved problem. This work aims to develop a new technique for assessing and reducing the risk involved in trusting others in a distributed environment. The thesis of this dissertation is that an electronic analogue of real-world guarantees, is a useful and interesting way to provide these assurances. We develop an extension of the notion of trust, which we call trust*, which is built upon local guarantees, and which provides a novel conceptual framework for analysing and reasoning about a wide variety of trust-related problems in distributed systems. We present the concept of trust* and apply it to a number of application scenarios where it would be beneficial. We simulate the trust* model in these environments for analysis. Also, we describe the key features and other issues related to the trust* model which became evident during its investigation and which are of wider interest.
MetadataShow full item record
Showing items related by title, author, creator and subject.
Which trust and when? : Conceptualizing trust in business relationships based on context and contingency Halliday, Sue (2003)This is a conceptual paper that sheds light on how trust works by distinguishing 'placed trust' from 'trust as response'. This distinction has implications for management practice and provides directions for future research. ...
Rogers, Kevin M. (2008)
Clarke, Stephen; Christianson, B.; Xiao, Hannan (Springer, 2013)We propose a new concept called trust* as a way of avoiding the necessity to transitively trust others in a range of distributed environments. The trust* approach uses guarantees based upon already established trust ...