Research And Implementation Of Ieee 802.15.4 Ccm-aes Coprocessor

Along with miniaturization of mobile device and the rapid development of pervasive computing, Wireless Sensor Networks (WSN) have drawn much attention. Because of the communication channel and the trustless environment, security issues have been a big problem on WSN nodes research. Till now, IEEE 802.15.4 protocol has been treated as standard for WSN application. It adopts CCM security mode by using Advanced Encryption Standard (AES). Both software and hardware resourses are limited in WSN nodes. Besides, the power is always suppled by buttery in WSN nodes. Thus, cost and energy consumption must be taken into account. Therefore, how to develop a separate low power, small area security coprocessor for WSN nodes has become a big challenge.According to the strict limitations, this paper designs an efficient implementation of small area, low power IEEE 802.15.4 CCM-AES security coprocessor. At first, we investigate the architecture and implementation methord of AES encryption core. After the S-box architecture has been selected, we implement three AES encryption cores with different number of S-box. Then, we choose the architecture of two-S-box and 8-bit wide data bus as encryption core for CCM by taking into account the tradeoff among area, power consumption and throughput. After that, we use two AES cores for encryption and authentication to implement CCM coprocessor. We parallize encryption and authentication then resue a key-expension to decrease the whole area of CCM and power consumption.We use Verilog HDL to describe the coprocessor. Then we use EDA tools to simulate the logic and synthesis. The results based on UMC 0.25μm technology show that, our implementation costs 14936 gates. Under a low frequency of 10MHz, the outhroughputs still can reach 7.2Mbps and the power consumption is 0.44mW/MHz. The experimental results show that, our IEEE 802.15.4 CCM-AES coprocessor fulfills the requirements of small area, low power and high security. It guarantees the communication security of WSN nodes.