WSN (Wireless sensor networks) are mostly distributed low power computer with the sensing task that rely on limited battery life and therefore are not able to implement full size security protocols. Depending on the kind of network heterogeneous, homogeneous and the environment they will be used in (likeliness of some attack scenarios) the security means used may depend a lot.
The question relates mostly to networks with homogeneous networks w/o internet connection that rely on some coarse distributed base stations or heterogeneous networks with only slightly differing nodes (towards computational power) that allow clusters to some extend but also heavily rely on coarse distributed base stations.
Does anyone have an idea what todays state of the art protocols are for the different kinds of possible attacks? Key distribution methods, Intrusion detection systems, ...?