The main purpose of an ad hoc network routing protocol is to enable the transport of data packets from one point to another. This paper examines the potential attacks on this transport service which arise from the realisation of threats from internal malicious nodes. The prerequisite of a routing service is a distributed mechanism for the discovery and… (More)
Mobile ad hoc networks have inherently very different properties to conventional networks. These new characteristics present major security vulnerabilities; in particular, one side effect of the unique way in which routing protocols operate in ad hoc networks is that many new threats arise. Selfish nodes are those which do not perform certain operations… (More)
One of the more mature instances of a service-oriented architecture is the model known as Grid Computing. Computational Grids and Data Grids are becoming commonplace in certain sectors, yet the style of security they implement is suitable only for a fairly small subset of possible user communities. Using some case studies and experience, we describe the… (More)
Trust flows in two directions in a Grid environment. The first is from the Grid user to the Grid resource, that is, the Grid trusts that the user will protect confidential information. The second is from the resource to the user, that is, the Grid will protect the user's Grid job and associated data. This paper comments on how Trusted Computing technology… (More)
—In this paper we examine issues of trust and reputation in Mobile Ad hoc Networks. We look at a number of the trust and reputation models that have been proposed and we highlight open problems in this area.
We propose a novel scheme that uses Trusted Computing technology to secure Grid workflows. This scheme allows the selection of trustworthy resource providers based on their platform states. The integrity and confidentiality of workflow jobs are provided using cryptographic keys that can only be accessed when resource provider platforms are in trustworthy… (More)
Previous work has reported on `Instant Knowledge', a context-aware social networking based recommendation system for enterprise. This paper outlines a hierarchical privacy architecture, to provide anonymity, unlink ability, unobservability and pseudonymity to IK users. Users are grouped according to `proportional distance reservation', which indicates how… (More)