Adam J. Lee Jodie P. Boyer Chris Drexelius Prasad Naldurg Raquel L. Hill Roy H. Campbell Supporting Dynamically Changing Authorizations in Pervasive Communication Systems. 134-150 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3450&spage=134 2005 conf/spc/2005 SPC db/conf/spc/spc2005.html#LeeBDNHC05