Embedded Tutorial: Integrated System Hardening Seen from a Security Point of View: Dream or Nightmare?

The main goal of this tutorial is to summarize some relationships and differences between reliability, safety and security and to emphasize the need for a more holistic design approach when hardening digital integrated systems having several requirements. Hardening for safety or reliability actually has advantages with respect to some security concerns, but usual proposals described in the literature do not meet all security needs. To achieve trustworthiness, additional constraints have to be taken into account during the design process to ensure an efficient protection against attacks, and still more important to avoid having counterproductive effects on the global security level. Some practical examples are discussed to illustrate the impact of security requirements on hardening at different steps of the design flow.