  Many applications of wireless sensor networks (WSNs) require deploying
sensors in hostile environments, where an adversary may eavesdrop
communications. To secure communications in WSNs, the q-composite key
predistribution scheme has been proposed in the literature. In this paper, we
investigate secure k-connectivity in WSNs operating under the q-composite
scheme, in consideration of the unreliability of wireless links. Secure
k-connectivity ensures that any two sensors can find a path in between for
secure communication, even when k - 1 sensors fail. We present conditions on
how to set the network parameters such that the network has secure
k-connectivity asymptotically almost surely. The result is given in the form of
a sharp zero-one law.
