An mixed access control method based on trust and role

The data security of distributed GIS system,especially access control,has become an indispensable function component in the practical application of distributed system.However,current approaches to access control are mostly based on individual user identity;hence they do not scale to distributed systems.In this paper,an access control mechanism which is the combination of trust and role-based access control model was presented.The extended model could meet the need to manage and enforce the strong and efficient access control technology in large-scale environments.