Secure Data Aggregation in Wireless Sensor Network

Wireless technology is evolving enormously and WSN have progressive applications in the area of surveillance and monitoring. A WSN is a system of sensor nodes for sensing, grouping and processing information. Data aggregation in WSN is employed to fuse data to form representative of whole data. In-network aggregation is supportive in conserving battery power and reducing communication overhead thus enhancing network lifetime. Tree-based aggregation is susceptible to error when looses sub-tree of readings because of node failure. Synopsis diffusion is a framework that avoids problems of tree based approach by incorporating multi-path routing and also avoids problem of double counting which is moderate in multiple routing. This is done by representing sensed value by a synopsis which is a bit vector of integers as zero or one and any particular reading is counted once. Synopsis diffusion has no stipulation of security and compromised node attack can’t be prevented using cryptography when security is such an important aspect in wireless sensor networks. This paper reviews the attack resilient computation algorithm which computes the true aggregate in presence of compromised nodes by filtering their false contributions. In specific concern, the algorithm allows the base station to compute the sum or count unharmed in presence of such an attack.