Gumel, L. A., S. K. Leow, and A. K. Ramani. “Do We Need Different Protocols To Support Group-Oriented Cryptosystem?”. Malaysian Journal of Computer Science, vol. 12, no. 1, June 1999, pp. 60-66, http://borneojournal.um.edu.my/index.php/MJCS/article/view/5752.