Hierarchical Multi-Party Key Establishment for Wireless Networks

A common property of practically all multi-party key agreement protocols is that they are non-hierarchical, i.e., they do not support user hierarchies. However, in real life it is likely that members of groups and organizations differ in ranking according to their job positions. Thus, it is reasonable that participants of a certain ranking could access more privileged information than participants of lower rankings. Hierarchical access control (HAC) schemes address this issue, but in contrast to provide secure distribution of hierarchically-arranged short-term session keys, HAC schemes provide secure distribution of hierarchicallyarranged long-term, predefined keys. In this paper, we present an efficient hierarchical multi-party key agreement protocol that is wellsuitable for wireless networks. We also present a closely related hierarchical centralized key distribution protocol for totally-ordered and partially-ordered security classes.