Research On Behavior-based Trust Model In Grid

Grid is the emerging technologies based on the development of distributed calculating technology, and it is also considered as infrastructure for next generation's internet and the basic facility of future calculating, which, in order to achieve full share of resources in computing, storage and data, makes the resource dispersed in all location become virtual as a powerful information system. Computer network is the carrier of Grid system, but security issues Grid system faced is much more serious than network system faced. Grid system not only needs the support of network communication technology, but also occupies a certain computing resource when application program is running on grid resources, and it does not only make use of computing power of CPU, memory and disk, but the system call of application program, in the case above, a legal registered user can attack the system by running application program on Grid environment if the user is malicious, so Grid need better security technologies to guarantee the safety of system.Trust is an important aspect of Grid environment, in computing environment of Grid, relationship of trust should be established among users, applications, network and resources. Currently the high-performance computing system is open to user based on trust model, per the experience, trust is an important method to guarantee safety in a well-managed computing environment of Grid, and also the research of trust has been the most popular topic in Grid security.Since M. Blaze put forward the concept of trust management, scholars had been developed their own trust evaluation model, which can well reflects the state of dynamic and instability of Grid environment by evaluation and measurement to information security, so the combine of trust evaluation model and security strategy is an useful and meaningful method to serve system security of Grid. At present, there are problems existed in integrality, rationality and operation in trust of some scholars, when unexpected accident happens in Grid environment, such as malicious node and joint deception, these trust does not perform perfectly.This paper put forward a trust dynamic quantitative model based on activity context through in-depth study to Grid trust. Based on Grid region, the said model transfers trust management in Grid into the forms of trust management between Grid region, and offers direct trust calculating formula and more update method, which both considers context of service and the decline of trust. According to the recommended trust gradation, the model puts forward the produce of recommended trust and calculating formula, which can guarantee security of recommended trust; it also solves trust evaluation problems in grid environment effectively by making the punishment system to malicious node and recommended action. By simulating experimentation the model is proved to be practical, and which can settle down the trust issues in Grid environment efficiently.