Cetratus: Towards A Live Patching Supported Runtime For Mixed-Criticality Safe And Secure Systems

Because of the high interconnectivity demanded in the Industrial Internet of Things (IIoT), security concerns arise for those safety-critical systems in which connectivity is required. These systems, which execute both safety and security functions, are defined as mixed-critical systems. Nevertheless, the adopted protection mechanisms may suddenly become out-of-date. From the security point of view, software updates are crucial to resolve those security issues that appear while long operational periods of mixed-critical systems. Besides, system halt and restarts due to software upgrades may not be admissible from the business and service point of view. As stated by the European Union Agency for Network and Information Security (ENISA), "the research in the area of patching and updating equipment without disruption of service and tools" is necessary. In this paper, we present Cetratus, a novel live patching supported framework for mixed-critical systems. The proposed solution aims at bringing up to date security protection measures without system shutdown, or compromising the safety integrity level.