Abstract: Secure and efficient data transmission is a critical issue for cluster-based wireless Sensor Networks (WSNs). In Cluster–based WSNs authentication of users is a very Important issue .So, by authenticating the sent user and the destination user , we can achieve the security and efficiency of data over CWSNs. To provide security of data and authentication of user we proposed a technique where we are implementing two concepts for performing those operations. The first one is identity based signature (IBS) for verification of user generated by the verifier and second one is a key is xor operated with the data and get the cipher and then binary level technique for encryption and decryption of the original message. The binary level technique converts the plain text into binary form and then splits the data into blocks and assign values to it based on identification mark (IM) technique which depends upon the length of the binary digits, then these are divided into two level, 1^st level is 2 bit and 2^nd level is 4 bit . Then at the receiver user the Cipher text will be decrypted by using the reverse technique and the destination user will get the original message. By providing those techniques we can improve efficiency, security overhead and energy consumption.

Key words: Identity based Signature (IBS), shared key generation, User authentication, message encryption and decryption.