Low Power AES Using 8-Bit and 32-Bit Datapath Optimization for Small Internet-of-Things (IoT)

Abstract

This paper proposes a low-power advanced encryption standard (AES) that can be utilized in smaller applications such as small-scale internet- of-things (IoT) devices. The proposed AES uses 8-bit and 32-bit datapaths to satisfy low power consumption and small area requirements. We use the 32-bit datapath in MixColumns only; the 8-bit datapath was used in other blocks such as SubBytes, Byte Permutation, AddRoundKey, and KeyExpansion. In addition, we propose optimized SubBytes and MixColumns to achieve low power consumption within a small area. To optimize SubBytes, we simplify the algorithm block-by-block to decrease the area. For the MixColumns, we present a 32-bit datapath that uses the proposed 0 × 02 and 0 × 03 multiplier. The AES that we have presented in this study, is implemented through Verilog-HDL and synthesized using the Samsung 65 nm standard cell library. The proposed AES shows 5400 2-input NAND gate equivalences and a power consumption of 10.01 μW (@ 0.9 V) at 10 MHz.