Boris Dragovic Evangelos Kotsovinos Steven Hand Peter R. Pietzuch XenoTrust: Event-based distributed trust management. 410-414 2003 conf/dexaw/2003 DEXA Workshops http://csdl.computer.org/comp/proceedings/dexa/2003/1993/00/19930410abs.htm db/conf/dexaw/dexaw2003.html#DragovicKHP03