关键词: 授权代理； 角色； 权限

Abstract:

The authors introduced a new delegation model based on the permissionbased delegation model (PBDM). The roles are divided into three sets, which include regular roles, private roles and delegation roles. The permissions are divides into two sets, which include delegatable permissions and undelegatable permissions. This new model supports usertouser and roletorole delegation, effectively avoids some problems such as name space explosion and void roles, ensures the safety of access to the system, and makes the delegation more flexible.

Key words: delegation, role, permission