Mingxing He Pingzhi Fan Firoz Kaderali Group Key Agreement Protocol Based on GH-KEP. 619-623 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3320&spage=619 2004 conf/pdcat/2004 PDCAT db/conf/pdcat/pdcat2004.html#HeFK04