A Feedback Based Secure Concurrency Control for MLS Distributed Database

Due to covert channel problem, traditional concurrency control protocols cannot be used in multilevel secure database system. Concurrency control protocol for multilevel secure database should ensure that transactions at lower security level are never delayed by higher security level transactions in the event of a data conflict. This may lead to the abortion or re- execution of high security level transactions over and over again making the secure concurrency control protocol unfair towards high security level transactions. In this paper we propose a feedback based secure concurrency control protocol for multilevel secure distributed databases, which ensure fairness property for transactions at different security level. Through a detailed simulation study we examine the fairness and performance of our feedback based secure concurrency control for a variety of workloads.