Semir Daskapan Ana Cristina Costa Willem G. Vree Amr Ali Eldin Virtual Trust in Distributed Systems. 30-39 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3184&spage=30 2004 conf/trustbus/2004 TrustBus db/conf/trustbus/trustbus2004.html#DaskapanCVE04