Abstract
The unauthorized propagation of information is an important problem in the Internet, especially because of the increasing popularity of On-line Social Networks. To address this issue, many access control mechanisms have been proposed so far, but there is still a lack of techniques to evaluate the risk of unauthorized flow of information within social networks. This paper introduces a probability-based approach to modeling the likelihood that information propagates from one social network user to users who are not authorized to access it. The approach is demonstrated via an example, to show how it can be applied in practical cases. Copyright 2011 ACM.