On the importance of considering physical attacks when implementing lightweight cryptography

Abstract : Pervasive devices are usually deployed in hostile environments where they are physically accessible to attackers. As lightweight cryptography is designed for such devices, it has to be particularly resistant to physical attacks. In this paper, we illustrate how active and passive physical attacks against the lightweight block cipher PRIDE can be carried. A side channel attack and a fault attack have been successfully implemented on the same software implementation of the algorithm. In both cases, we were able to recover the entire encryption key. First, we present our attacks, then we analyze them in terms of complexity and feasibility and finally, we discuss possible countermeasures.