On the Evolution of Adversary Models in Security Protocols (or Know Your Friend and Foe Alike)

Abstract

When I saw the announcement of this year’s workshop theme, I wondered about what I should be speaking about. [Laughter] One possibility was actually suggested by the presentations which were given before mine, particularly Yvo Desmedt’s, which point out the unfriendliness of some of today’s systems. With such “friends” who’s needs “adversaries”? Well, we actually we do need adversary definitions, and my theme is that not only do you have to know your “friend” the system (using the methods that perhaps Ross is going to talk about), but you have to know your “adversary” just as much in order to design and analyse meaningful security protocols. This presentation is related to some joint work which I have done with Adrian Perrig and his two graduate students, Haowen Chan, and Bryan Parno.