High integrity software is multi-faceted and can be multi-dimensional.  Safety and security are at the heart of this multi-dimensionality; however, their influences have often been considered to be at odds with one another.  This talk will look at some of the interactions between these dimensions and suggest an approach that exploits the synergies to provide "solutions" for both problems at the same time.

In a domain where products stay in service for many years/decades there has to be a mechanism that allows for updates — for correction, enhanced capability, hardware obsolescence or whatever.  Whilst being able to perform such updates is not in itself necessarily a safety or security critical problem, the impact on a system containing elements with those characteristics is significant and therefore such processes can be considered critical by association.

Using some practical examples it will become clear that safety can be enhanced by security and the latter can be improved by adoption of the techniques of the former, and together they can lead to better products that, if required, can be enhanced, corrected or updated in-situ across their prolonged lives.  All this can result in a lower through-life cost, and a better service and experience for our customers.