To solve the problems of high memory occupation,low connectivity and poor resiliency against node capture,which existing in the random key pre-distribution techniques while applying to the large scale Wireless Sensor Networks(WSNs),an Identity-Based Key Agreement Scheme(IBKAS) is proposed based on identity-based encryption and Elliptic Curve Diffie-Hellman(ECDH).IBKAS can resist man-in-the-middle attacks and node-capture attacks through encrypting the key agreement parameters using identity-based encryption.Theoretical analysis indicates that comparing to the random key pre-distribution techniques,IBKAS achieves significant improvement in key connectivity,communication overhead,memory occupation,and security strength,and also enables efficient secure rekeying and network expansion.Furthermore,we implement IBKAS for TinyOS-2.1.2 based on the MICA2 motes,and the experiment results demonstrate that IBKAS is feasible for infrequent key distribution and rekeying for large scale sensor networks.
