EDKM: efficient distributed key management for mobile ad hoc networks

Mobile ad hoc networks are dynamically reconfigured networks. Their major properties are mobility of devices, lack of central control authority, and existence of resource-constrained devices. Particularly, it is prudent to assume that there are no shared secret keys distributed by key distribution authority at initialization of the network. We propose a new efficient hierarchical binary tree model (EDKM) to form ad hoc group under such assumptions. Our trust model employs a new key distribution scheme to bring an alien device to the group and to exchange a secret key at that moment. EDKM is distributed, self-organizing, and can be deployed incrementally in the network. Moreover, EDKM provides complete backward and forward security in case of modification in membership and does not increase processing or storage requirements in comparison with other HBT schemes. The proposed group key management system is based on one-way hash function and secret key cryptography, and therefore, EDKM is practical, efficient and respectful to the constraints of mobile ad hoc networks.