International Association
for Cryptologic Research

Over the last twenty years, the research community has devised sophisticated methods for retrieving secret information from sidechannel emanations, and for resisting such attacks. This paper introduces a new CPU architecture called the Conjoined Microprocessor. The Conjoined Microprocessor can randomly interleave the execution of two programs at very low extra hardware cost. We developed for the Conjoined Microprocessor a preprocessor tool that turns a target algorithm into two (or more) separate queues like $Q_0$ and $Q_1$ that can run in alternation. $Q_0$ and $Q_1$ fulfill the same operation as the original target algorithm. Power-analysis resistance is achieved by randomly alternating the execution of $Q_0$ and $Q_1$, with different runs resulting in different interleavings. Experiments reveal that this architecture is indeed effective against CPA.