A Secure Real-Time Concurrency Control Protocol for Mobile Distributed Real-Time Databases

A class of security-critical applications with the requirements of timing constraints, such as wireless stock trading, power network scheduling, real-time traffic information management, etc., demand the support of mobile distributed real-time database systems. For the class of applications, mobile distributed realtime database systems must simultaneously satisfy two requirements in guaranteeing data security and minimizing the missing deadlines ratio of transactions. Multilevel secure database systems based on mandatory access control can prevent direct unlawful information flows between transactions. However, they can't be free from illegal information transfers between transactions belonging to different clearance levels by means of the concurrency control mechanism. This paper presents a secure hybrid optimistic real-time concurrency control protocol (SHORTCCP) for mobile distributed real-time database systems. The SHORTCCP not only fully considers the intrinsic limitations of mobile environments and the requirements of timing constraints of real-time transactions, but also makes an effective tradeoff between security and real-time performance by introducing secure influence factor and real-time influence factor. The experimental results show the SHORTCCP achieves data security without degrading real-time performance significantly.