Research On Dynamic Trust Model In Pervasive Computing Environment

With the rapid development of the wireless communication technology and thepopularity of small computing devices, such as smart phones, wireless sensors, RFID tags, thepervasive computing has already provided open, transparent, ubiquitous computing services,all these issues have made a solid foundation for the full realization of Internet of things. Anopen network environment is easy to be attacked maliciously, and a series of securityproblems cannot be ignored. But at this stage, research on pervasive computing security isstill on the primary level and lacks effective security measures. Firstly, there are lots of mobilenodes in pervasive computing environment, and the traditional centralized security measurescan not satisfy the requirements for distributed and adaptive property. Secondly, the storagecomputing ability is limited under pervasive computing environment; the existing algorithmfor trust model is too complex and wastes of much time and power to micro-computingdevices, which will seriously influence the efficiency of pervasive computing service. Finally,the security mechanisms of pervasive computing environment must take into the changes ofcontext. Some trust model has considered context information as a parameter, but it’s just apart of composite trust which is lack of the fetching and updating context in the trustmanagement process rationally.The main research work in this paper as follow:1. According to the characteristics of pervasive computing net-work environment such asubiquitous, transparency, mobility and self-adaptive, we summarize the security needs ofpervasive computing environment, and determine to select a trust-based trust model in thewireless sensor networks. We analyze the key points in the process in the model establishing,and determine every aspect of the design standards, according to the characteristics of trust inwireless sensor networks.2. Establish a hybrid dynamic trust model which is based on the global and local trust.According to the research of trust connotation, we give the definition and attributes of trust inthe model, which is complete and clear quantitative structure and metrics. We use differentstrategies of credible certification in different circumstances, so that a node could get thecorrect and effective trust level evaluation of someone which she wants to interactive with. 3. Research the collection, storage, updating and delivery method of credible informationto ensure that the pervasive environment could provide a credible service as well aspreventing the order on the application layer to be destroyed by malicious nodes and waywardnode.4. Establish the criteria of evaluation of trust model. We will verify feasibility andefficiency of the trust model according to the observation of the changing of trusted node,malicious node, wayward node, and the situation in the interactivity in simulated a networkenvironment.This paper designs a dynamic trust model which combines of global trust and local trustin pervasive computing environment according to the research listed above. A definition oftrust in the pervasive computing is given in the model, as well as the delivery, storage,updating method of trust. We also find a balance between the update arithmetic complexityand physical consuming in pervasive computing requirement, and discuss the method ofdealing with the malicious nodes. At last, we simulate a pervasive environment servicesituation on OMNet++simulation environment. In order to verify the feasibility and pervasiveadaptability of the model, we select service by using hybrid dynamic trust model and comparethe success rates of the service.