A method for authenticating users (130, 132, 134), the method comprising: registering, on a processing device, one or more users (130, 132, 134) in an authentication system, each of the one or more users (130, 132, 134) having at least one corresponding client device (120, 122, 124); receiving, on the processing device, location data from the at least one corresponding client device (120, 122, 124) from one or more of the one or more users (130, 132, 134); receiving, on the processing device, location data from one or more computer systems (110, 112, 114, 116); calculating, on the processing device, a distance from the one or more computer systems (110, 112, 114, 116) to the at least one corresponding client device (120, 122, 124) from the one or more of the one or more users (130, 132, 134) based on the location data from the at least one corresponding client device (120, 122, 124) from the one or more users (130, 132, 134) and the location data from the one or more computer systems (110, 112, 114, 116); receiving, by the processing device, an orientation or orientations of the at least one corresponding client device (120, 122, 124) of the one or more of the one or more users (130, 132, 134) relative to the one or more computer systems (110, 112, 114, 116); and sending, by the processing device, a notification to the at least one corresponding client device (120, 122, 124) from the one or more of the one more users (130, 132, 134) when the calculated distance from the one or more computer systems (110, 112, 114, 116) to the at least one corresponding client device (120, 122, 124) from the one or more of the one or more users (130, 132, 134) is within a first predetermined determined distance and the orientation or orientations of the at least one corresponding client device (120, 122, 124) of the one or more of the one or more users (130, 132, 134) relative to the one or more computer systems (110, 112, 114, 116) is a predetermined orientation or predetermined orientations, characterized in that the notification is a request to the at least one corresponding client device (120, 122, 124) from the one or more of the one more users (130, 132, 134) to provide an authenticator for access to the one or more computer systems (110, 112, 114, 116), wherein once the user (130, 132, 134) has been authenticated, the user (130, 132, 134) has access to one or more of the computer systems (110, 112, 114, 116). registering, on a processing device, one or more users (130, 132, 134) in an authentication system, each of the one or more users (130, 132, 134) having at least one corresponding client device (120, 122, 124); receiving, on the processing device, location data from the at least one corresponding client device (120, 122, 124) from one or more of the one or more users (130, 132, 134); receiving, on the processing device, location data from one or more computer systems (110, 112, 114, 116); calculating, on the processing device, a distance from the one or more computer systems (110, 112, 114, 116) to the at least one corresponding client device (120, 122, 124) from the one or more of the one or more users (130, 132, 134) based on the location data from the at least one corresponding client device (120, 122, 124) from the one or more users (130, 132, 134) and the location data from the one or more computer systems (110, 112, 114, 116); receiving, by the processing device, an orientation or orientations of the at least one corresponding client device (120, 122, 124) of the one or more of the one or more users (130, 132, 134) relative to the one or more computer systems (110, 112, 114, 116); and sending, by the processing device, a notification to the at least one corresponding client device (120, 122, 124) from the one or more of the one more users (130, 132, 134) when the calculated distance from the one or more computer systems (110, 112, 114, 116) to the at least one corresponding client device (120, 122, 124) from the one or more of the one or more users (130, 132, 134) is within a first predetermined determined distance and the orientation or orientations of the at least one corresponding client device (120, 122, 124) of the one or more of the one or more users (130, 132, 134) relative to the one or more computer systems (110, 112, 114, 116) is a predetermined orientation or predetermined orientations, characterized in that the notification is a request to the at least one corresponding client device (120, 122, 124) from the one or more of the one more users (130, 132, 134) to provide an authenticator for access to the one or more computer systems (110, 112, 114, 116), wherein once the user (130, 132, 134) has been authenticated, the user (130, 132, 134) has access to one or more of the computer systems (110, 112, 114, 116).