Some Like It Private: Sharing Confidential Information Based on Oblivious Authorization

The use of sensitive electronic information has skyrocketed in recent years, especially, in critical settings, such as law enforcement and national intelligence. To reconcile legitimate needs for sensitive information and related privacy concerns, appropriate privacy-preserving mechanisms need to be carefully designed and enforced. In this article, we explore the concept of Privacy preserving Policy-based Information Transfer (PPIT) to allow entities who lack mutual trust to share sensitive information. We describe two efficient PPIT constructs, discuss their security and present some experimental results. Finally, we propose an innovative construct that allows entities to efficiently verify the equality of their information.