  Wireless sensor networks are often deployed in public or otherwise untrusted
and even hostile environments, which prompts a number of security issues.
Although security is a necessity in other types of networks, it is much more so
in sensor networks due to the resource-constraint, susceptibility to physical
capture, and wireless nature. In this work we emphasize two security issues:
(1) secure communication infrastructure and (2) secure nodes scheduling
algorithm. Due to resource constraints, specific strategies are often necessary
to preserve the network's lifetime and its quality of service. For instance, to
reduce communication costs nodes can go to sleep mode periodically (nodes
scheduling). These strategies must be proven as secure, but protocols used to
guarantee this security must be compatible with the resource preservation
requirement. To achieve this goal, secure communications in such networks will
be defined, together with the notions of secure scheduling. Finally, some of
these security properties will be evaluated in concrete case studies.
