Roger Kilian-Kehr Joachim Posegga Smart Cards in Interaction: Towards Trustworthy Digital Signatures. 11-18 2002 conf/cardis/2002 CARDIS http://www.usenix.org/publications/library/proceedings/cardis02/kilian-kehr.html db/conf/cardis/cardis2002.html#Kilian-KehrP02