The Advanced Encryption System – AES is now used in almost all network-based applications to ensure security. In this paper, we propose a very efficient pipelined hardware implementation of AES-128. The design is versatile as it allows both encryption and decryption. The core computation of AES, which is performed on data blocks of 128 bits, is iterated for several rounds, depending on the key size. The security strength of AES has been proven proportional to the number of rounds applied. we show that if the required number of rounds must increase to defeat attackers, the proposed implementation stays efficient.