A New CPA Resistant Software Implementation for Symmetric Ciphers with Smoothed Power Consumption

A New CPA Resistant Software Implementation for Symmetric Ciphers with Smoothed Power Consumption

In this paper we propose a new method for applying hiding countermeasure against CPA attacks. This method is for software implementation, based on smoothing power consumption of the device. We propose a new heuristic encoding scheme for implementing block cipher algorithms. Our new method includes only AND-equivalent and XOR-equivalent operations since every cryptographic algorithm can be implemented with two basic operations, namely AND, XOR. In order to practically evaluate resistance improvement against CPA, we implement the proposed coding scheme on SIMON, a lightweight block cipher, on a smartcard with ATmega163 microprocessor. The results of this implementation show a 350 times more immunity against correlation attacks.