Wireless sensor networks are widely used in many modern settings. In order to build substantial networks each sensor must be cheap. So it follows that, since resources of individual sensor are limited, there is a need to create protocols that would use them sparingly and evenly in order to maximize lifetime of the network. To reach this goal some useful self-organizing tree-based protocols were created that use different properties of the network nodes, such as number of children, number of

more »

... from the ultimate sink, distance and remaining energy, to optimally select and reselect parent node in a network. However, there is also a challenge of providing security of the network. In this paper we propose a way of integrating a simple security method akin to iterative filtering into the protocol and discuss corresponding trade-off between attack prevention and increase of energy consumption.