Title: Beyond the Limits of DPA: Combined Side-Channel Collision Attacks
Abstract: The fundamental problem of extracting the highest possible amount of keyrelated information using the lowest possible number of measurements is central to sidechannel attacks against embedded implementations of cryptographic algorithms.To address it, this work proposes a novel framework enhancing side-channel collision attacks with divideand-conquer attacks such as differential power analysis (DPA).An information-theoretical metric is introduced for the evaluation of collision detection efficiency.Improved methods of dimension reduction for side-channel traces are developed based on a statistical model of Euclidean distance.The theoretical and experimental results of this work confirm that DPA-combined collision attacks are superior to both DPA-only and collision-only attacks.The new methods of dimension reduction lead to further complexity improvements.All attacks are treated for the case of AES-128 and are practically validated on a wide-spread 8-bit RISC microcontroller whose architecture is similar to that of many smart cards.