A method of facilitating authenticated communication between a user device and a service associated with a network via an intermediary system comprising either one or two intermediary apparatuses (203; 203-1, 203-2), the method comprising causing the intermediary system to: responsive to receiving an authentication request comprising data indicative of a user identity via a first communications link between the user device and the intermediary system, selectively configuring the intermediary system such that the user device is authorized to communicate with the intermediary system, wherein the authentication request is based on a first authentication protocol; thereafter: transmitting a request for a credential of a first type via a second communications link between the intermediary system and a server, wherein: the server is associated with the network and is arranged to authenticate the user device on the basis of a second authentication protocol, different to the first authentication protocol, and selectively allow the user device to communicate with the service in dependence on said authentication; said credential of the first type is for use by the intermediary system in obtaining a credential of a second type on behalf of the user device from the server, said request for the credential of the first type comprising data indicative of the user identity and being based on the second authentication protocol; responsive to receiving the credential of the first type, transmitting a request for the credential of the second type on behalf of the user device via said second communications link, said credential of the second type being for use by the user device in establishing authenticated communication with the service via a third communications link between the user device and the service, said request for the credential of the second type comprising data indicative of the user identity and being based on the second authentication protocol; and in response to receiving the credential of the second type, transmitting the credential of the second type to the user device via the first communications link. transmitting a request for a credential of a first type via a second communications link between the intermediary system and a server, wherein: the server is associated with the network and is arranged to authenticate the user device on the basis of a second authentication protocol, different to the first authentication protocol, and selectively allow the user device to communicate with the service in dependence on said authentication; said credential of the first type is for use by the intermediary system in obtaining a credential of a second type on behalf of the user device from the server, said request for the credential of the first type comprising data indicative of the user identity and being based on the second authentication protocol; the server is associated with the network and is arranged to authenticate the user device on the basis of a second authentication protocol, different to the first authentication protocol, and selectively allow the user device to communicate with the service in dependence on said authentication; said credential of the first type is for use by the intermediary system in obtaining a credential of a second type on behalf of the user device from the server, said request for the credential of the first type comprising data indicative of the user identity and being based on the second authentication protocol; responsive to receiving the credential of the first type, transmitting a request for the credential of the second type on behalf of the user device via said second communications link, said credential of the second type being for use by the user device in establishing authenticated communication with the service via a third communications link between the user device and the service, said request for the credential of the second type comprising data indicative of the user identity and being based on the second authentication protocol; and in response to receiving the credential of the second type, transmitting the credential of the second type to the user device via the first communications link.