The Reliable Computing Base - A Paradigm for Software-based Reliability

For embedded systems, the use of software-based error detection and correction approaches is an attractive means in order to reduce often inconvenient overheads in hardware. To ensure that such a software-based fault-tolerance approach is effective, it must be guaranteed that a certain amount of hardware and software components in a system can be trusted to provide correct service in the presence of errors. In analogy with the Trusted Computing Base (TCB) in security research, we call these components the Reliable Computing Base (RCB). Similar to the TCB, it is also desirable to reduce the size of the RCB, so the overhead in redundant hardware resources can be reduced. In this position paper, we describe approaches for informal as well as formal definitions of the RCB, the related metrics and approaches for RCB minimization.