Embodiments of the invention are concerned with providing access credentials associated with a user of a service to a server hosting the service, e.g. enabling single sign on by the user to a number of servers.The embodiments include functionality for establishing a first data connection with a terminal associated with the user and a second data connection with the server, and bridging the first and second data connections in order to establish a first communications session, using a first communications protocol, between the terminal and the server. A second communications session, using a second communications protocol, is also established with the server, via which a request for access credentials associated with the user is received. This request includes information received by the server in the first communications session, which is used to identify access credentials of the user that are transmitted to the server via the second communications session.