This research presents an encryption technique based on the programmable cellular automata (PCA) theory for realizing a hardware cryptosystem that can be applied in high-speed data communication networks. The PCA blocks proposed in this article makes the encryption system much more resistant on different types of attacks and the cellular automata's parallel information processing property give high speed. In this paper it is shown how a series of simple elements called "cells" interact using certain evolution rules and topologies to form a larger body that acts like an encryption system. The proposed architecture is implemented efficiently in hardware, in reconfigurable systems. An experimental hardware platform based on Xilinx FPGA XC3S500E was used for prototyping the proposed algorithm for both encryption and decryption modules. The results demonstrate that the proposed encryption algorithm has properties of large key space, high sensitivity to key, distribution of encrypted text in all ASCII intervals, resisting differential attacks, so the cryptosystem is practical and secure.