Lox incorporates each of the features described in this section into a novel privacy-preserving scheme. Lox allows users to build trust over time. Upon reaching a predetermined trust level, users are able to invite a number of friends. When a user is invited by a trusted user, they join Lox at a lower trust level and inherit their inviter’s bridges and the number of blocking events they have witnessed. These features are encoded as attributes in a user’s Lox credential, which allows the user to remain anonymous through their interactions with the system.