Two integrated schemes of user authentication and access control in a distributed computer network

With the growth in the scale of network technologies, security has become a major concern and a limiting factor. Computer networks provide convenient procedures for users operating at remote places. However, an intruder can easily access and intercept information transmitted in an open channel. Two integrated schemes for user authentication and access control are proposed, which are mechanisms used to provide for the protection of privacy and security in a distributed environment. One scheme is a dynamic approach which provides an efficient updating process for the modification of access rights. The second scheme allows servers to simplify verification processes for multiple access requests of a user at the same time. Both schemes are noninteractive approaches in which security is based on the computational difficulty of solving the discrete logarithm problem. Compared with other schemes proposed previously, the schemes are more secure and efficient and suitable for applications in a distributed environment. Intruders cannot derive secret information from public information. Intruders are not able to acquire the passwords of users from previously intercepted messages. By applying a time stamp, the schemes can withstand the replaying attack