This book constitutes the thoroughly refereed post-workshop proceedings of the 6th International Workshop on Security Protocols held in Cambridge, UK in April 1998. The 15 revised papers presented as position statements are followed by transcripts of the discussions between the authors and the audience. Also included is a report on the final panel discussion on future directions in security protocols research and developments. Thus the volume reflects the lively interaction at the workshop. The papers are devoted to the interrelations between trust and delegation, exploring the implications and effects of these upon such issues as authorization, security policy, and cryptosystems and component design.