Scalable Authenticated Tree Based Group Key Exchange for Ad-Hoc Groups

Task-specific groups are often formed in an ad-hoc manner within big structures, like companies. Take the following typical scenario: A high rank manager decides that a task force group for some project needs to be built. This order is passed down the hierarchy where it finally reaches a manager who calls some employees to form a group. The members should communicate in a secure way and for efficiency reasons symmetric systems are the common choice. To establish joint secret keys for groups, group key exchange (GKE) protocols were developed. If the users are part of e.g. a Public Key Infrastructure (PKI), which is usually the case within a company or a small network, it is possible to achieve authenticated GKE by modifying the protocol and particularly by including signatures. In this paper we recall a GKE due to Burmester and Desmedt which needs only O(log n) communication and computation complexity per user, rather than O(n) as in the more well-known Burmester-Desmedt protocol, and...

• Type: Conference
• Year: 2007
• Where: FC
• Authors: Yvo Desmedt, Tanja Lange, Mike Burmester
• Keywords: Authenticated Gke, FC 2007, Group Key Exchange, Task Force Group