Optimizing the Block Cipher Resource Overhead at the Link Layer Security Framework in the Wireless Sensor Networks

摘要

The security requirements in Wireless Sensor Networks (WSNs) and the mechanisms to support the requirements, demand a critical examination. Therefore, the security protocols employed in WSNs should be so designed, as to yield the optimum performance. The efficiency of the block cipher is, one of the important factors in leveraging the performance of any security protocol. In this paper, therefore, we focus on the issue of optimizing the security vs. performance tradeoff in the security protocols in WSNs. As part of the exercise, we evaluate the storage requirements of the block ciphers viz. the Advanced Encryption Standard (AES) cipher Rijndael, the Corrected Block Tiny Encryption Algorithm (XXTEA) using the Output Codebook Block (OCB) mode. We compare our results with the Skipjack cipher in Cipher Block Chaining (CBC) mode. Our results clearly show the light-weight cipher XXTEA, as the optimal cipher and the Output Codebook Mode as the optimal mode of operation for the link layer security protocols. To the best of our knowledge, ours is the first experimental evaluation of the AES cipher Rijndael, the corrected block Tiny Encryption Algorithm (XXTEA) and the OCB mode in the link layer security architecture for WSNs.