Self-healing Group Key Distribution

In this paper we propose the self-healing feature for group key distribution through Subset Difference (SD) method proposed by D. Naor et al. The subset difference method is one of the efficient proposals for group key distribution, however, recently a polynomial based solution for key distribution was proposed by D. Liu et al., which has the similar message size but also provides self-healing feature. We compare the two schemes and show that, SD has better performance in key recovery operation and is secure against the collusion of any number of revoked users. By incorporating the feature for self-healing to SD, it will be a more practical solution for the networks where packet loss is common. In addition to the self-healing feature, we also present some optimization techniques to reduce the overhead caused by the self-healing capability. Finally, we discuss the idea of mutual healing and mention certain requirements for that method for key recovery.