Abstract.We are presenting an implementation of the Galois/Counter Mode (GCM) for the Advanced Encryption Standard (AES) in IPsec in this paper. GCM is a so called "authenticated encryption" as it can ensure confidentiality, integrity and authentication. It uses the Counter Mode for encryption, therefore counters are encrypted for an exclusive-OR with the plaintext. We describe a technique where these encryptions are precomputed on a Graphic Processing Unit (GPU) and can later be used to encrypt the plaintext, whereupon only the exclusive-OR and authentication part of GCM are left to be computed. This technique should primarily not limit the performance to the speed of the AES implementation but allow Gigabit throughput and at the same time minimize the CPU load.

A fair amount of current High Performance Computing systems take advantage of coprocessors. Most of them use either GPU or FPGA but rarely benefit from both, since the management of such flexible systems is exceedingly challenging. The Cuteforce Analyzer is a multipurpose cluster system. Different node types allow a variety of cluster configurations to cope with various kinds of tasks. Compute nodes utilize low priced off-the-shelf GPU and/or FPGA as specialized coprocessors to accelerate the execution of algorithms.This paper presents the experiences in implementing the Cuteforce Analyzer and the usage of both coprocessor types in a single cluster system based on MS Windows HPC.