Analysis and improvement of an access control scheme with user authentication

Both user authentication and access control are required for data protection in computer systems. Recently, Ham and Lin proposed an access control scheme with integration of user authentication. In their scheme, the above two functions are combined together to prevent possible security threats between these two protection modules. This paper, argues that there are some redundant information and verification operations in their scheme. A more compact and efficient alternative, with the same security and characteristics, is presented. Also, a batch-type multiple-access request verification is suggested to improve the efficiency of the system and a password updating process is proposed to facilitate the dynamic operations