In general, the security is concerned of all types of information and data systems. Many standards to security are ranging from military to commerce and private communications. One essential aspect for secure communications is the private key cryptography. Recently most security applications and standards are defined to independent algorithm, which is allowing a choice from a set of cryptographic algorithms for the same purpose. Since Data Encryption Standard (DES) is still the most widely used private-key encryption algorithm, DES has a significant role in security applications. Field Programmable Gate Arrays (FPGA) is reconfigurable hardware devices and interesting phenomenon in embedded development. In the present work, DES algorithm implementation optimization has been achieved through the DES unit components replication to four concurrent DES functional units. This operation has been performed by using a spatial parallelism approach. The input/output data has been stored in the separated RAMs which it is dual port memories that supports the read and write processes concurrently. This approach is speedup the processing of data. Furthermore, the frequency which is supported by the board has been duplicated from 50 up to 200 MHz by utilizing the Phase Locked Loop (PLL) to avoid any delay of DES functional unit implementation. All of this has led to enhance and speedup the implementation of DES algorithm and increase throughput as well. The design and implementation is performed on Altera Nios II Embedded Evaluation Kit (NEEK) board.
