Sadie Creese Michael Goldsmith Bill Roscoe Irfan Zakiuddin Authentication for Pervasive Computing. 116-129 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2802&spage=116 2003 conf/spc/2003 SPC db/conf/spc/spc2003.html#CreeseGRZ03