Frederick Butler Iliano Cervesato Aaron D. Jaggard Andre Scedrov Verifying Confidentiality and Authentication in Kerberos 5. 1-24 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3233&spage=1 2003 conf/isss2/2003 ISSS db/conf/isss2/isss2003.html#ButlerCJS03