Paper 2009/231

Practical DPA Attacks on MDPL

Elke De Mulder, Benedikt Gierlichs, Bart Preneel, and Ingrid Verbauwhede

Abstract

MDPL is a masked logic style that unites principles of dual-rail pre-charge as well as masked logic to achieve resistance against differential power analysis attacks. MDPL has received much attention and numerous papers discussing the security provided by MDPL as well as its weaknesses have been published. As a matter of fact, most of these papers are purely theoretical or provide evidence based on simulations. At present, it is unclear to what extent these concepts affect the security provided by MDPL in practice. We fill this gap and present results of an extensive case study of attacks against an MDPL prototype chip. We demonstrate successful DPA attacks and show that MDPL implementations, resistant to standard DPA attacks, can be broken in practice. Further, we show that the underlying concept of the folding attack, i.e. analysis of probability densities, indeed exposes MDPL's greatest weakness: the masking renders the circuit more vulnerable to attacks than a circuit with a fixed mask. In addition, our analysis leads to novel insights into the power consumption properties of MDPL in real silicon.