The next-generation Internet must connect not only machines, but also users: families, friends, representatives, and rights advocates. There are immense technical challenges in facilitating communication while protecting user privacy and guarding user security. Online social networks today forge ahead on this path, providing users with new protocols and applications, but often without putting the privacy of their users first. This research will lay the foundation for decentralized online social networks: no third parties will necessarily be trusted with personal information, users will be able to craft detailed access policies for their social data, users will have assurance that their friends are not impostors, and users will continue to access functionality similar to current social networking applications. This work is being done with colleagues at the University of Maryland.