Abstract: As we have limited energy resources and computational power, data aggregation from multiple sensor nodes is done using simple methods such as averaging. WSN’s are usually unattended, they are highly vulnerable to node compromising attacks. Thus making it necessary to ascertain trustworthiness of data and reputation of sensor nodes is crucial for WSN. Iterative Filtering algorithms were found out to be very helpful in this purpose. Such algorithms perform data aggregation and provide trustworthiness assessment to the nodes in the form of weight factors.These algorithms simultaneously aggregate data from multiple sources and provide a trust estimation of these sources, usually in a form of corresponding weight factors assigned to data provided by each source. In this paper we analyzed some secure data aggregation mechanisms and introduced a new complicated collision attack with its impact on wireless sensor networks.

Keywords: Collusion Attacks,data aggregation,Iterative Filtering Algorithm,wireless sensor network.