In this paper, we propose an area-efficient design of Advanced Encryption Standard (AES) processor by applying a new common-expression-elimination (CSE) method to the sub-functions of various transformations required in AES. The proposed method reduces the area cost of realizing the sub-functions by extracting the common factors in the bit-level XOR/AND-based sum-of-product expressions of these sub-functions using a new CSE algorithm. Cell-based implementation results show that the AES processor with our proposed CSE method has significant area improvement compared with previous designs.

In this paper, we present a pure hardware implementation of the advanced encryption standard (AES) with 8-bit data path with both encryption/decryption abilities for applications of wireless network. To achieve the requirements of low area resource and high throughput performance, the 8-bit AES design overlaps the MixColumns (MC) and ShiftRows (SR), Inverse MixColumns (IMC) and Inverse ShiftRows (ISR) operations in order to reduce the required clock cycles and critical path delay of transformations involved. The combinations of SB with ISB, MC with IMC, and SR with ISR can effectively reduce the area cost of the AES realization. We implement the AES processor in an ASIC chip. The design has the area cost of 4.3 k-gates with throughput of 72Mbps which can meet the throughput requirement of IEEE 802.11g wireless network standard. From the experimental results, we observe that our AES design has better performance compared with other previous designs.