Anonymity Analysis in Credentials-based Systems: A Formal Framework
V. Benjumea, J. Lopez, and J. M. Troya.
Abstract
Anonymity has been formalized and some metrics have been defined in
the scope of anonymizing communication channels. In this paper, such
formalization has been extended to cope with anonymity in those
scenarios where users must anonymously prove that they own certain
privileges to perform remote transactions. In these types of
scenarios, the authorization policy states the privileges required to
perform a given remote transaction. The paper presents a framework to
analyze the actual degree of anonymity reached in a given transaction
and allows its comparison with an ideal anonymity degree as defined by
the authorization policy, providing a tool to model, design and
analyze anonymous systems in different scenarios.
Keywords: anonymity metrics, anonymity degree, adequacy degree, anonymous
credential systems