Addition with blinded operands

Abstract

The masking countermeasure is an efficient method to protect cryptographic algorithms against Differential Power Analysis (DPA) and similar attacks. For symmetric cryptosystems, two techniques are commonly used: Boolean masking and arithmetic masking. Conversion methods have been proposed for switching from Boolean masking to arithmetic masking, and conversely. The way conversion is applied depends on the combination of arithmetic and Boolean/logical operations executed by the underlying cryptographic algorithm. This paper focuses on a combination of one addition with one or more Boolean operations. Building on a secure version of a binary addition algorithm (namely, the and-xor-and-double method), we show that conversions from Boolean masking to arithmetic masking can be avoided. We present an application of the new algorithm to the XTEA block-cipher. © 2014 Springer International Publishing Switzerland.