Certification of Translators via Off-line and On-line Proof Logging and Checking

Using non failure-safe components in the implementation of safety-critical systems is desirable because of the extremely high cost of certified components. In order to enhance the safety of such systems, we adopt a solution based on the idea of verifying each single execution of the software running upon them. In particular, we consider the class of translation-based tools used in the development of safety-critical systems. In order to perform the verification in an automatic and efficient way, we follow an innovative approach, by distinguishing an off-line and an on-line verification phases. Each proof in the two phases is guaranteed correct thanks to the use of a logging-and-checking architecture for the tools used to generate them. We describe in detail the off-line and on-line logging-and-checking methodology, its application in the frame of an industrial project, and the ongoing logging-and-checking redesign of a state-of-the-art prover which we intend to use in future applications