What Should a Good Security Model Be?

In this article we survey a number of security models – which range from the first models to newly proposed approaches – in an attempt to answer the question of what we want our security model to be. The emphasis of this work is not on past or current security models, but rather on new approaches that have been proposed in the literature but have not yet found their way to the end user. The models described in this work provide unusual ways of addressing security needs and may be difficult to employ due to drastic differences from the currently accepted norms. These models, however, may have useful properties that the current systems do not possess, and might provide more efficient ways of securing our systems.