Secure Real-time transaction processing

Abstract

Real-Time Database Systems (RTDBS) are designed to process transactions with strict completion deadlines, often in safety-critical and military applications where security is paramount. However, ensuring both real-time performance and security presents conflicting challenges. This thesis addresses these challenges for applications with firm deadlines, where transactions missing their deadlines are aborted and considered useless. The study focuses on two key components of RTDBS: secure concurrency control (CC) and secure buffer management (BM). A novel CC protocol, S2PL-WAIT, is proposed, allowing simultaneous use of different mechanisms for enforcing security and optimizing real-time performance. Simulation results demonstrate that S2PL-WAIT consistently outperforms existing protocols across various workloads and configurations. Additionally, a secure buffer management policy, SABRE, is introduced. SABRE incorporates optimizations that maintain security with minimal impact on real-time performance, especially in systems with limited security levels. To address fairness - where higher-security transactions often miss deadlines Real-Time Database Systems (RTDBS) are designed to process transactions with strict completion deadlines, often in safety-critical and military environments where security is paramount. However, mechanisms for enforcing security and meeting real-time constraints frequently conflict, making it challenging to design efficient secure RTDBS. This thesis addresses these challenges for applications with firm deadlines, where transactions missing their deadlines are aborted and considered useless. The study focuses on designing high-performance secure concurrency control (CC) protocols and buffer management (BM) policies. A novel CC protocol, S2PL-WAIT, is introduced, enabling simultaneous use of different mechanisms for enforcing security and optimizing real-time performance. Simulation results show that S2PL-WAIT consistently outperforms existing protocols across various workloads and configurations. Additionally, the SABRE buffer management policy is proposed, incorporating optimizations that maintain security with minimal impact on performance, especially in systems with limited security levels. To address fairness - where higher-security transactions disproportionately miss deadlines - the thesis introduces GUARD, a feedback-based admission control policy. GUARD ensures fairness without violating military-grade information leakage constraints and maintains near-optimal real-time performance. The protocols and policies presented offer a robust framework for secure, high-performance real-time transaction processing. This work represents the first comprehensive study in the area of secure firm real-time database systems and has been published in leading conferences including VLDB, ACM SIGMOD, and national forums on real-time systems.