Tag, You Can See It! Using Tags for Access Control in Photo Sharing

Users often have rich and complex photo-sharing preferences, but properly configuring access control can be difficult and time-consuming. In an 18-participant laboratory study, we explore whether the keywords and captions with which users tag their photos can be used to help users more intuitively create and maintain access-control policies. We find that (1) tags created for organizational purposes can be repurposed to create efficient and reasonably accurate access-control rules; (2) users tagging with access control in mind develop coherent strategies that lead to significantly more accurate rules than those associated with organizational tags alone; and (3) participants can understand and actively engage with the concept of tag-based access control.