This paper addresses the problem of secure path key establishment in WSN using a key pre-distribution scheme.
In this paper first we have proposed a symmetric key generation scheme using Maximum Rank Distance(MRD) codes and then we have proposed a path establishment algorithm. Our scheme not only substantially improves the memory usage requirements but also reduces the communication overhead to setup a common link key, it only requires 2 messages to setup a link key between two nodes(One from each node). It is shown with example and simulation results that our scheme provides high level of network connectivity and scalability.