Applicability of the IEC 62443 standard in Industry 4.0 / IIoT.

Today's industrial automation systems are undergoing a digital transformation that implies a shift towards the Internet of Things (IoT), leading to the Industrial Internet of Things (IIoT) paradigm. Existing Industrial Automated Control Systems (IACS), enriched with a potentially large number of IoT devices are expected to make systems more efficient, flexible, provide intelligence, and ultimately enable autonomous control. In general, the majority of such systems come with high level of criticality that calls for well-established methods and approaches when achieving cybersecurity, preferably prescribed by a standard. IEC 62443 is an industrial standard that provides procedures to manage risks related to cybersecurity threats in IACS. Given the new IIoT paradigm, it is likely that existing standards are not sufficiently aligned with the challenges related to developing and maintaining cybersecurity in such systems. In this paper we review the applicability of the IEC 62443 standard in IIoT contexts and discuss potential challenges the process owners might encounter. Our analysis underlines that some areas within the standard could prove difficult to reach compliance with. In particular, handling of cross zone communication and software updates require additional guidance.