Pekka Nikander Jari Arkko Delegation of Signalling Rights. 203-214 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2845&spage=203 2002 conf/spw/2002 Security Protocols Workshop db/conf/spw/spw2002.html#NikanderA02