Extending Weight-Balanced Key Tree without Adjustment-Propagation

An Extending weight-balanced tree (EWBtree) for group key managements is presented. By introducing a special path in the weight-balanced key tree, theEWB tree does not cause adjustment-propagation aftermember adding or member deleting. The bounds ratioof the EWB tree based algorithm to that of the optimaltree shows that the bounds of EWB tree is better thanthose of the height-balanced 2-3 tree and equal to those ofthe weight-balanced 2-3 tree. The analysis also shows thatthe proposed scheme has fewer rekeying cost than the onesbased on the weight-balanced 2-3 tree, height-balanced 2-3tree, LTM tree and NSBHO tree.