Hash Algorithms for 8051-based Sensornodes

Wireless Sensors Networks are still an emerging technology. Their special architecture allows for unique applications that would be impossible, or at least very difficult, to implement using other technologies. But the wireless data transmission between the single nodes poses new challenges from a security point of view: the single messages have to be secured against eavesdropping and manipulation, as well as the individual nodes have to be secured against capture and extraction of their secret key. Cryptographic hash functions are an integral part of most cryptographic network protocols, whether they are used for signatures or message integrity. In this position paper, we describe a preliminary performance evaluation of three very different hash-functions on a Texas Instruments CC2530 sensor node, based on an 8051 microcontroller: Tiger, representing a hash designed for 64-bit architectures, the current standard SHA-1, and Grøstl, a SHA-3 finalist. Our preliminary results indicate that even without any major optimizations hash algorithms that were clearly not designed to run on constrained devices can be adapted to these environments with quite acceptable results, thereby giving designers of sensor network security protocols new implementation options.