A study on secure group mutual exclusion algorithm

Abstract

A distributed system can be viewed as a set of processes that share many types of resources, such as processors, memory cells, buses, and printers. Emerging network technologies require efficient distributed processing ability. A distributed algorithm in distributed system deals with how to make the computers connected together work well. Main focus of distributed algorithm is mutual exclusion problem that means many shared resources must be accessed in a mutually exclusive manner. This thesis gives a new quorum-based distributed group mutual exclusion algorithm. In the group mutual exclusion problem, multiple processes can enter critical section at the same time if they belong to the same group. The former quorum-based group mutual exclusion algorithm has a case when two processes cannot enter critical section at the same time even if they can do so. We call the above situation as unnecessary blocking. We give a new algorithm which prevents unnecessary blocking. Also, in this thesis, we present a method to control the access to a secure database based on group mutual exclusion algorithm using quorum systems. The security of algorithm is based on the secret sharing scheme. The main goal of our algorithm is to integrate security with distributed algorithm.