Advanced Encryption Standard Galois Counter Mode – Optimized GHASH Function Technology Guide

Description

Galois/Counter Mode (GCM) is a mode of operation for authenticated encryption. In this mode, data is encrypted via Advanced Encryption Standard (AES) block cipher and an authentication tag is generated by applying a hash function (GHASH) to the entire ciphertext. This paper introduces novel techniques to further improve the performance of GHASH. These techniques present algorithmic improvements, which can be utilized in any setting for GCM implementation.