A Multi-step Simulation Approach toward Secure Fault Tolerant System Evaluation

As new techniques of fault tolerance and security emerge, so does the need for suitable tools to evaluate them. Generally, the security of a system can be estimated and verified via logical test cases, but the performance overhead of security algorithms on a system needs to be numerically analyzed. The diversity in security methods and design of fault tolerant systems make it impossible for researchers to come up with a standard, affordable and openly available simulation tool, evaluation framework or an experimental test-bed. Therefore, researchers choose from a wide range of available modeling-based, implementation-based or simulation-based approaches in order to evaluate their designs. All of these approaches have certain merits and several drawbacks. For instance, development of a system prototype provides a more accurate system analysis but unlike simulation, it is not highly scalable. This paper presents a multi-step, simulation-based performance evaluation methodology for secure fault tolerant systems. We use a divide-and-conquer approach to model the entire secure system in a way that allows the use of different analytical tools at different levels of granularity. This evaluation procedure tries to strike a balance between the efficiency, effort, cost and accuracy of a system´s performance analysis. We demonstrate this approach in a step-by-step manner by analyzing the performance of a secure and fault tolerant system using a JAVA implementation in conjunction with the ARENA simulation.