关键词: 图, 图变换, 访问控制

Abstract: To provide a direct and precise description for workflow access control, an access control model for workflow systems was developed based on graph and graph transformation. The model was represented by using graph which provided a formal basis for proving the semantic correctness of the model. The model was formally described by graph and graph transformation and relevant algorithms to the model were also presented. In this model, a type of graph was specified to represent the type information of elements in the graph transformation for workflow access control, a set of rules with variable were used to express the transformation of system authorization status and a series of positive and negative constraints were set up to depict wanted and unwanted framework in authorization graph. The graph based authorization constraints of access control in workflow and template of graph transformation rules were also set up. The verification algorithm of constraints consistency was proposed. And the method by using termination to verify access control rationality was also presented. Finally, an application example was provided to verify the feasibility of the model.

Key words: graph, graph transformation, access control, workflow