Accelerating AES Using Instruction Set Extensions for Elliptic Curve Cryptography

The Advanced Encryption Standard (AES) specifies an algorithm for a symmetric-key cryptosystem that has already found wide adoption in security applications. A substantial part of the AES algorithm are the MixColumns and InvMixColumns operations, which involve multiplications in the binary extension field GF(2). Recently proposed instruction set extensions for elliptic curve cryptography (ECC) include custom instructions for the multiplication of binary polynomials. In the present paper we analyze how well these custom instructions are suited to accelerate a software implementation of the AES. We used the SPARC V8-compatible LEON-2 processor with ECC extensions for verification and to obtain realistic timing results. Taking the fastest implementation for 32-bit processors as reference, we were able to achieve speedups of up to 25% for encryption and nearly 20% for decryption.