We present a solution to the problem of content sharing in digital rights management (DRM) systems. Users in DRM systems purchase content from content providers and then wish to distribute it between their own devices or to other users. The goal is to allow the sharing of such content, with the control of the content provider, while ensuring that it complies with the content's usage rules. We also address in this paper the subject of protecting users' privacy during the content sharing; to the best of our knowledge no study thus far addressed this topic. While most of the previous studies on content sharing in DRM systems assume the existence of authorized domains, ours does not make that assumption. The solutions that we present here are based on Certified Sharing Requests which are used when devices request from the content provider to share content with other devices. Our solutions enhance the usability of DRM, from both the users' and content provider's perspective, by supporting on-the-fly sharing, sharing and re-sharing of controlled content, a pay-per-share business model, and privacy preservation.

Abstract. We present a solution to the problem of content sharing in digital rights management (DRM) systems. Users in DRM systems purchase content from content providers and then wish to distribute it between their own devices or to other users. The goal is to allow the sharing of such content, with the control of the content provider, while ensuring that it complies with the content's usage rules. While most of the previous studies on content sharing in DRM systems assume the existence of authorized domains, ours does not make that assumption. The solutions that we present here are based on Certified Sharing Requests which are used when devices request from the content provider authorization to share content with other devices. Our solutions enhance the usability of DRM, from both the users' and content provider's perspective, by supporting on-the-fly sharing, sharing and re-sharing of controlled content, and a pay-per-share business model.