Secure Web 2.0 Content Sharing Beyond Walled Gardens

Web 2.0 users need usable mechanisms for sharing their content with each other in a controlled manner across boundaries of content-hosting or application-service providers (CSPs). In this paper, we describe the architecture, design, and implementation of a proposed system for Web 2.0 content sharing across CSPs. With our approach, users use their existing email account to login to CSPs, and content owners use their email-based contact-lists to specify access policies. Users are assumed to be equipped only with a Web browser and CSPs do not need to change their existing access-control mechanisms. In addition, policy statements are URI-addressable, and the same access policies can be reused and enforced across CSPs.