Catherine Meadows Dusko Pavlovic Deriving, Attacking and Defending the GDOI Protocol. 53-72 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3193&spage=53 2004 conf/esorics/2004 ESORICS db/conf/esorics/esorics2004.html#MeadowsP04