  The purpose of a wireless sensor network (WSN) is to provide the users with
access to the information of interest from data gathered by spatially
distributed sensors. Generally the users require only certain aggregate
functions of this distributed data. Computation of this aggregate data under
the end-to-end information flow paradigm by communicating all the relevant data
to a central collector node is a highly inefficient solution for this purpose.
An alternative proposition is to perform in-network computation. This, however,
raises questions such as: what is the optimal way to compute an aggregate
function from a set of statistically correlated values stored in different
nodes; what is the security of such aggregation as the results sent by a
compromised or faulty node in the network can adversely affect the accuracy of
the computed result. In this paper, we have presented an energy-efficient
aggregation algorithm for WSNs that is secure and robust against malicious
insider attack by any compromised or faulty node in the network. In contrast to
the traditional snapshot aggregation approach in WSNs, a node in the proposed
algorithm instead of unicasting its sensed information to its parent node,
broadcasts its estimate to all its neighbors. This makes the system more
fault-tolerant and increase the information availability in the network. The
simulations conducted on the proposed algorithm have produced results that
demonstrate its effectiveness.

Cryptography and Security;Networking and Internet Architecture