Abstract. Key pre-distribution schemes are a favored solution for establishing secure communication in sensor networks. Often viewed as the safest way to bootstrap trust, the main drawback is seen to be the large storage overhead imposed on resource-constrained devices and also these schemes are quite insecure because pre-loading global secrets onto exposed devices strengthens the incentive for attackers to compromise nodes. To overcome these drawback, we propose a new key predistribution scheme for pairwise key setup in sensor networks. In our scheme each sensor node is assigned with small number of randomly selected generation keys instead of storing big number of random keys and a shared secrete key can be efficiently computed from it. After generating the keys with neighbors the initial keys rings are being deleted from nodes memory. The analysis of our approach shows that it improves the previous random key pre-distribution schemes by providing the more resiliency against node cap...