| Popis: |
Shoulder-surfing is a well-known technique to steal passwords by observing authentication sessions. While researchers have proposed many shoulder-surfing resistant password schemes, there is no general model to illustrate existing schemes and to help developing new schemes. In this paper, we introduce a graph-based model that generally describes shoulder-surfing resistant password schemes. Using this model, we present a method for analyzing some particular security threats and show some properties of, and relationship between certain security measures. Applying our proposed model to existing password systems, we demonstrate how the model can help analyze password schemes. We also discuss the usefulness of our model in designing a new password schemes. |
