Security Analysis of Provably Secure Constant Round Dynamic Group Key Agreement
J. C. M. TEO, Chaowei Tan, J.M. Ng · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences · 2006
Recently, Dutta and Barua proposed provably secure constant round authenticated group key agreement protocols in dynamic scenario. In this letter, we show that their Leave Protocol does not provide forward secrecy, that is, a leaving user can still obtain the new session key used in subsequent sessions.