Wireless sensor networks simplify the collection and analysis of data from multiple locations. The self-organization capabilities of wireless sensor networks enable rapid deployment of target tracking and intrusion detection in hostile environments. However, sensor nodes deployed in adversarial environments, it must be fortified against various attacks. This paper examines the threats against attacks and countermeasures to protect their communications with origin integrity and data integrity. This paper solves the data security problem in wireless sensor networks deployed for surveillance and target tracking by application of appropriate security mechanisms.