A mobile network operator system (MNO system; 200) for authenticating a consumption device, the MNO system comprising - a computer network interface for communicating with the consumption device over a computer network, - a mobile network interface for communicating with the authentication device, the authentication device having a mobile network identifier, - a processor configured to - receive an initiating authentication request from the consumption device over the computer network, the initiating authentication request comprising the mobile network identifier, - send a first authentication request to the authentication device associated with the mobile network identifier and receive a first authentication response from the authentication device in response to the first authentication request, - send a second authentication request to the authentication device associated with the mobile network identifier, wherein the second authentication request comprises an MNO computer network address, - receive a second authentication response from the consumption device at the MNO computer network address in response to a user interaction with the consumption device in response to receiving the second authentication request at the authentication device, - verify the first authentication response and the second authentication response and verify that the second authentication response and the initiating authentication request were received from the same consumption device, - send an authentication success message comprising an authentication token. - a computer network interface for communicating with the consumption device over a computer network, - a mobile network interface for communicating with the authentication device, the authentication device having a mobile network identifier, - a processor configured to - receive an initiating authentication request from the consumption device over the computer network, the initiating authentication request comprising the mobile network identifier, - send a first authentication request to the authentication device associated with the mobile network identifier and receive a first authentication response from the authentication device in response to the first authentication request, - send a second authentication request to the authentication device associated with the mobile network identifier, wherein the second authentication request comprises an MNO computer network address, - receive a second authentication response from the consumption device at the MNO computer network address in response to a user interaction with the consumption device in response to receiving the second authentication request at the authentication device, - verify the first authentication response and the second authentication response and verify that the second authentication response and the initiating authentication request were received from the same consumption device, - send an authentication success message comprising an authentication token. - receive an initiating authentication request from the consumption device over the computer network, the initiating authentication request comprising the mobile network identifier, - send a first authentication request to the authentication device associated with the mobile network identifier and receive a first authentication response from the authentication device in response to the first authentication request, - send a second authentication request to the authentication device associated with the mobile network identifier, wherein the second authentication request comprises an MNO computer network address, - receive a second authentication response from the consumption device at the MNO computer network address in response to a user interaction with the consumption device in response to receiving the second authentication request at the authentication device, - verify the first authentication response and the second authentication response and verify that the second authentication response and the initiating authentication request were received from the same consumption device, - send an authentication success message comprising an authentication token.