Implementation of modified RC4 algorithm for Wireless Sensor Networks on CC2431

Abstract

Advancements in wireless communication and computing devices have made Wireless Sensor Network (WSN) interesting. Since WSN is deployed in hostile environments, the security becomes a common concern. WSN demands for lightweight security schemes due to the fact that the nodes in the networks are resource constrained. In order to provide secure data transmission in wireless sensor networks, cryptographic algorithms has to be incorporated. RC4 is one of the commonly used stream cipher due to its speed and simplicity in implementation. The drawback of RC4 is weakness in the permutation of internal state table during initial phase. To overcome the limitations in existing RC4, RC4 stream cipher with modified state table is proposed. The system reduces the known outputs of the internal state and also improves the execution speed. Modification is made on computational steps of the initialisation phase. The modified method tends to provide high degree of randomness in the permutation of the state variable than the original RC4. The algorithm design is targeted to encrypt/decrypt 8-bit ADC reading of TICC2431.