  Security concern for a Sensor Networks and level of security desired may
differ according to application specific needs where the sensor networks are
deployed. Till now, most of the security solutions proposed for sensor networks
are layer wise i.e a particular solution is applicable to single layer itself.
So, to integrate them all is a new research challenge. In this paper we took up
the challenge and have proposed an integrated comprehensive security framework
that will provide security services for all services of sensor network. We have
added one extra component i.e. Intelligent Security Agent (ISA) to assess level
of security and cross layer interactions. This framework has many components
like Intrusion Detection System, Trust Framework, Key Management scheme and
Link layer communication protocol. We have also tested it on three different
application scenarios in Castalia and Omnet++ simulator.
