A Novel Tree-based Authenticated Dynamic Group Key Agreement Protocol for Wireless Sensor Network

Group key agreement protocol allows all the members to agree upon a common session key, which may be used for later secure communication among all the participants. Since TGDH (tree based Diffie-Hellman) has been proposed by Yongdae Kim, Adrian Perrig, and Gene Tsudik, there are several group key agreement protocols proposed to improve the security and performance of TGDH. In this paper, we first propose authenticated two-party and three-party key agreement protocols based on bilinear pairing. Then, using authenticated two party or three party key agreement protocols to compute the key of a node which has two or three child nodes, we propose a novel tree-based authenticated group key agreement protocol. Our protocol provides implicit key authentication, which TGDH cannot provide. Through substituting ternary tree for binary and substituting bilinear pairing and ellipse curve DH for DH, our protocol is more efficient both in term of computation and communication than TGDH.