Systems, methods, and computer-readable media are disclosed for authenticating access to a service provider system, or more specifically, to a user account maintained on the service provider system, using a single key authentication mechanism. The service provider system may receive an authentication image from a user application executing on a user device. The authentication image may include first data generated in response to user input to the user device, second data generated by the user application, and third data generated by the service provider system. The service provider system may then authenticate access to the user account based at least in part on the authentication image and send an indication to the user device that access to the user account has been authenticated. Authenticating access to the user account includes determining that the first data, second data, and third data match respective data expected by the service provider system.