A method of two-factor authentication for gaining access to an application using at least a first device and a second device registered to a user. The first and second devices each have a plurality of sensors for detecting activity modalities of the user on the first and the second devices and are in communication with a server computer. In the method, the server computer: receives credentials and detected activity modality for gaining access to the application from the first device; sends a request to the second device registered to the user for activity modality of the user; receives the detected activity modality from the second device; compares the detected activity modality of first device to the detected activity modality of the second device; and if the detected activity modalities of first device and the second device match, granting access to the user on the first device to the application.