A New Hybrid Cryptography Technique in Wireless Sensor Network

The wireless sensor network is a large number of tiny nodes installed in insecure environment for monitoring, gathering and transferring data and are prone to security threats for its limited resources. In order to transmit the data and to protect from different attacks in the network, security is maintained. To achieve confidentiality, authenticity and authorization of data which secure the data from different attacks cryptographic algorithm were used. The number of keys used in the cryptographic algorithm determines the security of the data. Cryptographic algorithms are broadly classified into two types symmetric cryptography and asymmetric cryptography. In the symmetric key cryptographic algorithm, a secret key is shared in the network and in asymmetric key cryptographic algorithm two keys are used for data security. In wireless sensor network, symmetric key cryptography required more storage to store the key among all the nodes of the network and in asymmetric key cryptography more computation time is require for the data encryption and decryption. To avoid memory and computation overhead we proposed a hybrid cryptosystem to handle the security in the wireless sensor network. Initially shared key is exchanged among nodes using ECC which is a public key algorithm. Data is encrypted and decrypted using RC4 symmetric key algorithm. Various performance measures such as time taken for encryption and decryption process and memory needed for storing cipher text data. The proposed model shows faster encryption of data and takes less memory for key storage as compared to the traditional approach.