Dynamic Fault Injection Countermeasure - A New Conception of Java Card Security

Nowadays Fault Injection is the main threat for any sensitive applications being executed on embedded devices. Indeed, such an attack allows one to efficiently recover any secret or to gain unauthorized privileges if no appropriate countermeasure is implemented. In the context of Java Card applications, the main method to counteract Fault Injection consists in adding redundancy for sensitive operations and integrity verification for sensitive variables. While being efficient from a security point of view, such a method substantially impacts the performance of the application. In this article we introduce a new pragmatic approach to counteract Fault Injection by dynamically increasing the security level of the application. This methodology, based on upgrading the Java Card Virtual Machine, allows us to optimize the performance of sensitive applications in every day life while providing a strong security level as soon as an attacker tries to disturb their executions.