Advanced Encryption Standard instruction Set Extensions for EC Cryptography: Optimizing AES Implementation using Custom Instruction Set Extensions

Abstract

This paper demonstrate that the case by showing the use of word-level binary polynomial multiplication for acceleration of the Advanced Encryption Standard (AES) algorithm. Considerable fraction of the computation effort of a software implementation of AES is spent in the MixColumns and InvMixColumns transformations. Consequently, these transformations are a worthwhile target for optimization as demonstrated by the approaches of T-table lookup or alternative representation of the AES State. Performance of MixColumns implementations lies in the fact that the required multiplications in the binary extension field GF(28) are not supported by modern processors and need to be emulated by shift and XOR instructions. Instruction set extensions for Elliptic Curve Cryptography (ECC) include support for arithmetic in large binary extension fields. This analyzes how well these custom instructions are suited for accelerating a software implementation of AES on 32-bit platforms. Taking fast AES implementations for 32-bit processors as reference.