A Secure Group Key Management Scheme for Wireless Cellular Systems

In wireless networks, secure multicast protocols are more difficult to implement efficiently due to the dynamic nature of the multicast group and the scarcity of bandwidth at the receiving and transmitting ends. Mobility is one of the most distinct features to be considered in wireless networks. Moving users onto the key tree causes extra key management resources even though they are still in service. To take care of frequent handoff between wireless access networks, it is necessary to reduce the number of rekeying messages and the size of the messages. The multicast protocol used in wired networks does not perform well in wireless networks because multicast structures are fragile as the mobile node moves and connectivity changes. When we choose a key management scheme, the structure of the wireless network should be considered very carefully. In this paper, we design a key management tree such that neighbors on the key tree are also physical neighbors on the cellular network. By tracking the user location, we localize the delivery of rekeying messages to the users who need them. This lessens the amount of traffic in wireless and wired intervals of the network. The group key management scheme uses the pre-positioned secret sharing scheme.