Weakness of shim¡¦s New ID-based tripartite multiple-key agreement protocol

In this article we show that Shim’s new ID-based tripartite multiple-key agreement protocol still suffers from the impersonation attack, a malicious user can launch an impersonation attack on their protocol. Keyword: ID-based, Weil-paring, impersonation attack, tripartite authenticated key agreement, unknown key share attack.