Abstract: Disclosed are methods related to controlling user access to a first computer device, using a second computer device. One method comprises generating authentication data in accordance with a first algorithm and generating acceptable response data in accordance with a second algorithm using the authentication data and information shared with a second computer device. The authentication data is received at the second computer device, where response data is generated in accordance with the second algorithm using the shared information and the received authentication data. The response data generated by the second device is received at the first computer device and compared with the acceptable response data. Access to the first computer device is granted if the response data is identical to the acceptable response data.