Aritra Dhar¹ and Pinaki Sarkar², ¹Gurunanak Institute of Technology, India and ²Jadavpur University, India

Wireless Sensor Networks (WSN) are constraint by the limited resources available to its constituting sensors. Thus the use of public-key cryptographyduring message exchange gets forbidden. One has to invoke symmetric key techniques. This leads to key distribution in the sensors which in itself is a major challenge. Again due to resource constraints, Key Predistrubution (KPD) methods are preferred to other distribution techniques. It requires predistribution of keys in nodes prior to deployment and establishing immediately once deployed. However there are certain weaknesses in various existing KPD schemes. For instance, often it is not guaranteed that any given pair of nodes communicate directly. This leads one to revert to multi-hop communication involving intermediate sensor nodes resulting in increased cost of communication. In this work a key predistribution technique using Reed-Solomon codes is considered which is faced with the above weakness. The authors suggests a novel technique of merging certain number of sensors into blocks ensuring that the blocks have full connectivity amongst themselves. Here the blocks are chosen in such a way that it ensures no intra-node communication. Further this approach improves both time and space complexity of the system.

Communication, Reed-Solomon Codes,Merging blocks, Key Predistribution,Security.