Analysis of Software-Implemented Fault Tolerance: Case Study on Smart Lock

In our research, we focus on Fault-Tolerant system design and testing. Recently, we also studied Fault Tolerance against random and deliberate faults of electronic smart locks. In our last research, we tested Software-Implemented Fault Tolerance in the controller of a smart electronic lock. We found out that the most sensitive part is the Instruction Memory, but also that our hardening proved to have only negligible effects on the resulting fault tolerance. In this paper, we extend our experiments and provide further analysis of potential pitfalls when hardening using SIFT. We found out that added hardness may improve resilience to faults. But also, the resilience may be instantly worsened by other factors, such as increased bus traffic. In our research we found out, that our hardening did not improve the resiliency to faults most likely due to the increased bus traffic. This means that it is always important to consider the complete system and also the parts of the system that are easily overlooked.