Patent ID: 8806584

Claim:
A method comprising: accessing, by one or more computing devices, a graph structure comprising a plurality of nodes and a plurality of edges connecting the nodes, each of the edges between two of the nodes representing a single degree of separation between them, the nodes comprising a first-user node corresponding to a first user associated with an online social network and one or more second-user nodes that each correspond to a second user associated with the online social network; receiving, by one or more computing devices, a request from an external service provider identifying the first user, wherein the first user is requesting to access content on the external service provider; accessing, by one or more of the computing devices, a white list comprising a first set of user IDs of a first set of users, each user of the first set of users corresponding to a user associated with the external service provider; and authenticating, by one or more of the computing devices, the first user to access content on the external service provider if the first-user node is connected in the graph structure to one or more nodes corresponding to users of the first set of users by a series of nodes and edges that does not comprise a node corresponding to a user on a gray list comprising user IDs of the users who are not authorized to access content on the external server, wherein the gray list is based on a black list.