A Vulnerability Optimization Method for Security-Critical Real-Time Systems

In this paper, we focus on task scheduling problems in security-critical real-time systems. We consider that all of the critical tasks are equipped with RC5 algorithm to reduce the vulnerability when facing security attacks. The relationships among security level, vulnerability and execution time of each task are firstly deduced. Then, a Multiple Task Vulnerability Optimization Method (MTVOM), which is based on dynamic programming algorithm, is devised to obtain minimal vulnerability under strict timing constraints. Furthermore, we take task criticality into consideration because each task is not equally important to its system. Finally, simulation experiments demonstrate the effectiveness of this method.

I. Introduction

Nowadays, distributed embedded real-time systems are facing increasing security problems. More and more of these systems are connected to internet, which increases the possibility of security attacks. For distributed systems, there are megabytes of data transferred through insecure network. Some of them are quite sensitive and disclosure of them may produce huge damage. In particular, in the business world and the government, where data is considered sensitive, the potential data losses due to a security incident could be catastrophic [1]. In order to prevent unauthorized access to the information and guarantee security of them, cryptography is surely adopted.