Towards secure and communication-efficient broadcast encryption systems

Many emerging network applications are based upon a group communication model where security is a critical design issue. We address the broadcast encryption problem of distributing to a group of network entities a confidential cryptographic key, which needs to be updated from session to session. The design goals of such a system essentially include not only security but also communication efficiency concerning the distribution of the session key. We show that there is a disconnect between the essence of broadcast encryption and a scheme proposed very recently. The observation also motivates us to seek for secure and efficient broadcast encryption solutions. Three distinctive constructions, based on the bilinear map, the one-way hash function, and the RSA cryptosystem, respectively, are then presented to demonstrate reasonable tweaks and various tradeoffs when designing practical group-oriented communication systems. These constructions exhibit not only promising security but also impressive communication efficiency, and we also discuss the diverse networking scenarios to which they are applicable. (C) 2012 Elsevier Ltd. All rights reserved.