Worst-case execution time analysis of security policies for deeply embedded real-time systems

Abstract

Deeply embedded systems often have unique constraints because of their small size and vital roles in critical infrastructure. Problems include limitations on code size, limited access to the actual hardware, etc. These problems become more critical in real-time systems where security policies must not only work within the above limitations but also ensure that task deadlines are not missed. A critical piece of information for security policies in real-time systems is the worst-case execution time (WCET) of the security code. This paper addresses some of the issues faced in the implementation of such security policies and also the process of determining WCETs for them.