Security research in to wired networks indicates that there are always some weak points in the systems that are hard to predict. This is particularly true for a wireless network, in which open wireless transmission media and low physical-security protection of mobile devices pose additional challenges for prevention-based approaches and detection-based approaches. Sensor network security mechanisms can be divided into two categories: communication protocols and key management architectures. Communication protocols deal with the cryptographic algorithms used to achieve availability, confidentiality, integrity, and authentication. Key management architectures handle the complexities of creating and distributing keys used by communication protocols. In this we explore Taxonomy of security solutions, Taxonomy of key distributing schemes, Detecting Computer and Network Misuse, Monitoring misuse through expert systems, Anomaly-based Intrusion Detection Using Mobility Profiles of Public Transportation Users, How to Increase Security in Mobile Networks by Anomaly Detection, The Baye’s Decision Rule.