Security Protocols

Welcome back to the International Security Protocols Workshop. Our theme for this, the 14th workshop in the series, is "Putting the Human Back in the Protocol". We've got into the habit of saying "Of course, Alice and Bob aren't really people. Alice and Bob are actually programs running in some computers." But we build computer systems in order to enable people to interact in accordance with certain social protocols. So if we're serious about system services being end-to-end then, at some level of abstraction, the end points Alice and Bob are humanafterall.Thishascertainconsequences.Weexploresomeoftheminthese proceedings, in the hope that this will encourage you to pursue them further. Is Alice talking to the correct stranger? Our thanks to Sidney Sussex College, Cambridge for the use of their faci- ties, and to the University of Hertfordshire for lending us several of their sta?. Particular thanks once again to Lori Klimaszewska of the University of C- bridge Computing Service for transcribing the audio tapes, and to Virgil Gligor for acting as our advisor.