A Framework for Group Key Management Protocol Assessment Independent of View Synchrony

Abstract

Problem statement: As group key management extended into the area of large dynamic networks, complex issues emerged involving the many operations that run over several network topologies. The issues that occurred due to multiple topologies were also compounded by differing views of the network, taken at different time slices or positions within the network. This was especially complex when figuring in mobile, ad-hoc networks. View synchrony is the current operational technique, or assumption, applied to group key exchange protocols. However, before this analysis view synchrony was just that, an assumption and the literature for group key exchange lacked an inquiry into what could happen when view synchrony was removed. Current group key management protocols rely on view synchrony and yet all protocols vary in requisite operational descriptions and performance measures. In this study, a framework for group key management protocol operations and performance measures was defined and examined how that framework could be used to compare and contrast existing protocols with and, more importantly, without view synchrony. Approach: Current literature lacked categories by which to quantify the performance metric of the protocols. This study first defined the dynamic key operations that all protocols share. By these definitions, group key management protocols were directly compared. Once definitions existed, this study assembled a list of costs that every protocol requires to establish and share keys across the dynamic group. These results provided an understanding of view synchrony's role and whether or not it should be solely relied on in these current protocols. Results: The prior conclusion that view synchrony was an integral part of all group key management protocols was shattered, when seen through the lens of communication costs and assumptions in wireless ad-hoc networks. View synchrony, as an assumed part of all group key management was previously inconsistently portrayed. The ability to see this before did not exist because a framework upon which to evaluate the costs did not exist. Now, literature can proceed with clearly defined understandings of what values exist in group key management protocols. Conclusion/Recommendations: Better communication in group key management will be a benefit to the entire field. Now that costs can be analyzed, procedure and security can be improved and protocols can be implemented for wireless ad-hoc networks. In addition, it led two authors of this study to create a new protocol, DTEGK, to maximize the most efficient communication, as view synchrony was hindering the effectiveness of previous protocols. Without the hindrance of view synchrony and a quantitative list of defined communication costs, protocols can also now be extended into the wireless, ad-hoc realm of group key management.