Low Power High Speed MISTY1 Cryptography Approaches

Abstract

The demand for high performance, low power/secured handheld equipment increased the need for high speed/low energy and efficient encryption/decryption algorithms. Recently, efficient techniques were suggested to increase the standard of security as well as the speed of portable and handheld devices. Also, those techniques cause increment in the lifetime of battery by reducing the total silicon capacitance and minimizing the switching activity. This paper presents two approaches to reduce the number of logic gates at S7 and S9 of MISTY1 in order to reduce the total delay time, power dissipation and silicon area. The Logic Gate Reduction Approach (LGRA) reduces the number of logic gates by applying Boolean Algebra rules and simplifications, while the Duplicated Gate Reduction Approach (DGRA) removes the redundant XOR and AND logic gates which form the S7 and S9 blocks ciphers. The LGRA approach shows that the throughput enhanced by 21.1% compared to the conventional design, the silicon area reduced by 26.8%, while the dynamic power dissipation is reduced by 21.7% on average. The DGRA approach shows that the throughput enhanced by 3.8% compared to the conventional design, the silicon area reduced by 31.7%, while the dynamic power dissipation is reduced by 27% on average. As a result, the proposed approaches could be fit for next generation of handheld and portable devices.