Exploring Robustness in Group Key Agreement

Secure group communication is crucial for building distributed applications that work in dynamic environments and communicate over unsecured networks (e.g. the Internet). Key agreement is a critical part of providing security services for group communication systems. Most of the current contributory key agreement protocols are not designed to tolerate failures and membership changes during execution. In particular, nested or cascaded group membership events (such as partitions) are not accommodated. In this paper we present the first robust contributory key agreement protocols resilient to any sequence of events while preserving the group communication membership and ordering guarantees. Submission and Contact Information Primary/Secondary Areas: Security/Fault-Tolerance Contact author: Yair Amir Phone: 410-516-4803 Fax: 410-516-6134 Email: [email protected] This work was supported in part by a grant from the National Security Agency under the LUCITE program and by grant F30602-00-2-0526 from The Defense Advanced Research Projects Agency. Department of Computer Science, Johns Hopkins University, Baltimore, MD 21218, USA. Email: fyairamir, crisn, jschultz, [email protected] Computer Networks Division, USC Information Sciences Institute, Marina Del Ray, CA 90292-6695, USA. Email: [email protected] Information and Computer Science Department, University of California, Irvine Irvine, CA 92697-3425, USA. Email: [email protected]