A tow-level security approach for wireless sensor networks

In recent decades, the significant expansion and popularity of wireless sensor networks in various applications have attracted the attention of many researchers. Energy and security restrictions are main challenges for the researchers. The application of these networks in inaccessible and dangerous environments and wireless communications between nodes have led them to be subjected to direct attacks; also wireless sensor networks in addition to external attacks face a new challenge of internal attacks that actually have made the methods such as encryption and authentication insufficient and thus new security procedures are needed. Recently, trust as a new and efficient method and a soft security mechanism could deal with internal attacks and provide optimum security in these networks. In this scheme a new security method is provided for wireless sensor networks composed of two main levels. In the first level a key agreement and a new authentication method based on elliptic curve cryptography are used to deal with external attacks. In the second level, a trust-based method is provided to deal with internal attacks. Comparison and simulation suggest that the proposed design in addition to focusing on reducing the energy consumption was successful in increasing network security and resistance against many attacks.