On Applying Boolean Masking to Exponents.

Implementations of block ciphers typically use Boolean shares of intermediate states to prevent side-channel analysis. Implementations of public-key cryptographic algorithms are typically protected by using the algebraic properties of the algorithms. In this work, we present an exponent splitting technique with minimal impact on performance based on Boolean shares. This method can be combined with other countermeasures to make a side-channel resistant implementation with minimal increase in execution time.