Improving security for periodic tasks in embedded systems through scheduling

Abstract

While many scheduling algorithms for periodic tasks ignore security requirements posed by sensitive applications and are, consequently, unable to perform properly in embedded systems with security constraints, in this paper, we present an approach to scheduling periodic tasks in embedded systems subject to security and timing constraints. We design a necessary and sufficient feasibility check for a set of periodic tasks with security requirements. With the feasibility test in place, we propose a scheduling algorithm, or SASES (security-aware scheduling for embedded systems), which accounts for both security and timing requirements. SASES judiciously distributes slack times among a variety of security services for a set of periodic tasks, thereby optimizing security for embedded systems without sacrificing schedulability. To demonstrate the effectiveness of SASES, we apply the proposed SASES to real-world embedded systems such as an automated flight control system. We show, through extensive simulations, that SASES is able to maximize security for embedded systems while guaranteeing timeliness. In particular, SASES significantly improves security over three baseline algorithms by up to 107%.