Secure concurrency control protocol with timeliness guarantees in real-time database systems

Abstract

Real-time database systems (RTDBSs) are usually applied in the time-critical applications with security constraints. For these applications, RTDBSs must simultaneously satisfy two requirements in guaranteeing data security and minimizing the deadline miss ratio for admitted transactions. Multilevel secure database systems based on mandatory access control can prevent direct unlawful information flows between transactions. However, they cannot be free from illegal information transfers between transactions by means of the concurrency control mechanism, so the novel concurrency control algorithms supporting security and real-time requirements are needed for RTDBSs. In this paper, we present a novel secure real-time concurrency control algorithm (SRCC) for RTDBSs. The SRCC makes an effective tradeoff between security constraints and timing constraints by introducing secure control factor and real-time influence factor. Further, in order to obtain the better real-time performance, an enhanced SRCC called ESRCC is proposed by introducing the concept of similarity. The experimental results show that the ESRCC can ensure excellent real-time performance while guaranteeing data security.