Yair Amir Cristina Nita-Rotaru Jonathan Robert Stanton Framework for Authentication and Access Control of Client-Server Group Communication Systems. 128-140 2001 conf/ngc/2001 Networked Group Communication http://link.springer.de/link/service/series/0558/bibs/2233/22330128.htm db/conf/ngc/ngc2001.html#AmirNS01