Probing attack of share‐serial threshold implementation of advanced encryption standard

Abstract

The authors present the first security evaluation of the side-channel attack countermeasure called the share-serial threshold implementation proposed by Wegener and Moradi. In the share-serial threshold implementation, all the component functions are processed using a unified circuit thereby reducing total circuit area. They show that the share-serial threshold implementation is vulnerable to probing attack using a single probe. In the proposed attack, an attacker places a single probe on a wire in the unified circuit and read the target wire over multiple cycles. The attacker can recover unshared 1-bit intermediate value by combining the measured data. The attack highlights an interesting difference between side-channel analysis and probing attack. The authors also evaluate the number of cipher calls to attack the block cipher advanced encryption standard (AES).