关键词: 网格, 虚拟组织, 访问控制, 策略集, 自动组合, 权限合并

Abstract: To realize dynamic generation of the access control policies and improve the dynamic adaptability of authorization verification for requester in grid，the automatic composition scheme for access control policy set in grid was put forward. According to the services composition constraints, the composition relationships of policy set for autonomous domains of Virtual Organization (VO) was constructed. The theory of algebra set was used to implement composition and computing for the policy set. And the automatic composition for policy set was realized by means of automatic composition engine and automatic trigger rules，and the access control polices set in VO was therefore generated. As there might be conflicts and redundancy policy subset in composed polices set，a method to resolve conflicts and automatic permission combination was proposed. The automatic composition algorithm was also presented. By analysis and implementation of the scheme, it was demonstrated that the scheme was with higher flexibility and dynamic adaptability.

Key words: grid, access control, virtual organization, policy set, automatic composition, permission combination