The demand for efficient cryptographic solutions has been continuously growing in the last decade. Encryption must usually be performed at high data rates, a requirement often met with the help of cryptographic hardware. Accelerators, such as Field Programmable Gate Arrays (FPGAs) and Graphics Processing Units (GPUs), are special purpose processors designed to speed up sections of applications. FPGAs are highly customizable, while GPUs provide massive parallel execution resources and high memory bandwidth. In this paper, the authors compare the performance of these architectures, presenting a performance study of SEAL, a fast, software-oriented encryption algorithm on a Virtex-6 FPGA.