Efficient and Secure Code Dissemination in Sensor Clouds

In this paper, we present an efficient and secure code dissemination technique aimed at sensor clouds. Previous code dissemination techniques were geared toward traditional wireless sensor networks. They did not take into account, the dynamic nature of a sensor cloud, where the applications running on the motes may not just be updated but changed completely in successive code disseminations. The technique presented in this paper is based upon the observation that a large amount of code is common between applications in wireless sensor networks. Our technique first discovers the code common across various wireless sensor applications. It then distributes this code in the form of functions a priori into the network. During code dissemination, these common functions are picked up by the sensors from the network. Only a part of the code needs to be transmitted from the base station. This reduces the overall transmitted code and hence the energy consumption. Since, security is important in sensor clouds, we further present a security scheme based on proxy reencryption to provide confidentiality and integrity of the code. We have implemented our scheme using two different proxy reencryption algorithms, on Mica2 and TelosB mote platforms to measure its energy consumption. We have also evaluated our scheme in terms of disseminated code size and bandwidth usage to illustrate its efficiency compared to a popular secure code dissemination technique, Seluge.