SMART SECURITY MANAGEMENT IN SECURE DEVICES

International audienceAmong other threats, secure components are subjected tophysical attacks whose aim is to recover the secret information theystore. Most of the work carried out to protect these components generally consists in developing protections (or countermeasures) taken one byone. But this “countermeasure-centered” approach drastically decreasesthe performance of the chip in terms of power, speed and availability.In order to overcome this limitation, we propose a complementary approach: smart dynamic management of the whole set of countermeasuresembedded in the component. Three main specifications for such management are required in a real world application (for example, a conditionalaccess system for Pay-TV): it has to provide capabilities for the chip todistinguish between attacks and normal use cases (without the help of ahuman being and in a robust but versatile way); it also has to be basedon mechanisms which dynamically find a trade-off between security andperformance; all these mecanisms have to formalized in a way which isclearly understandable by the designer. In this article, a prototype whichenables such security management is described. The solution is based ona double-processor architecture: one processor embeds a representativeset of countermeasures (and mechanisms to define their parameters) andexecutes the application code. The second processor, on the same chip,applies a given security strategy, but without requesting sensitive datafrom the first processor. The chosen strategy is based on fuzzy logic reasoning to enable the designer to describe, using a fairly simple formalism,both the attack paths and the normal use cases. A proof of concept hasbeen proposed for the smart card part of a conditional access for Pay-TV,but it could easily be fine-tuned for other applications