  This paper considers secure energy-efficient routing in the presence of
multiple passive eavesdroppers. Previous work in this area has considered
secure routing assuming probabilistic or exact knowledge of the location and
channel-state-information (CSI) of each eavesdropper. In wireless networks,
however, the locations and CSIs of passive eavesdroppers are not known, making
it challenging to guarantee secrecy for any routing algorithm.
  We develop an efficient (in terms of energy consumption and computational
complexity) routing algorithm that does not rely on any information about the
locations and CSIs of the eavesdroppers. Our algorithm guarantees secrecy even
in disadvantaged wireless environments, where multiple eavesdroppers try to
eavesdrop each message, are equipped with directional antennas, or can get
arbitrarily close to the transmitter. The key is to employ additive random
jamming to exploit inherent non-idealities of the eavesdropper's receiver,
which makes the eavesdroppers incapable of recording the messages. We have
simulated our proposed algorithm and compared it with existing secrecy routing
algorithms in both single-hop and multi-hop networks. Our results indicate that
when the uncertainty in the locations of eavesdroppers is high and/or in
disadvantaged wireless environments, our algorithm outperforms existing
algorithms in terms of energy consumption and secrecy.
