The characteristics of cloud computing such as openness

sharing

make the access control more complicated in cloud computing than it in traditional environment. In order to guarantee the security and reliability of cloud users and the data on the cloud server in the accessing process

this paper put forward an access control model named CT-RBAC in cloud computing. This scheme divided the security level of the data on the cloud server and cloud users

and introduced the set of task situation

whats more

it achieved the access control policy from five aspects. Finally

it gave out the implementation process of cloud users access the data in the cloud. The analysis results indicate that CT-RBAC has its obvious advantages. This scheme improves the monitoring ability of the object owner to the cloud server

guarantees the security and reliability of data

and ensures the well flexibility.