Who Are You? It Depends (On What You Ask Me!): Context-Dependent Dynamic User Authentication.

Traditionally, the approaches to user authentication have been more static, which have often proved to be less secure. More recently, some researchers [3] have explored allowing users to choose one of several available authentication schemes. In the recent past, researchers have also considered context-dependent attributes in user authentication. Context is information that allows a system to “characterize the situation of an entity, where an entity can be a person, place, or physical, or computational object” [4]. Using context-dependent attributes makes a system more dynamic and adaptive; it makes it possible for systems to associate levels of trust with user actions to grant access to requested resources [1] and to design adaptive systems to authenticate users based on their location and other attributes [5].