Abstract: A method for authenticating a user in a payment transaction using a computing device includes: storing location data entries, each entry including a geographic location of a mobile device and a time; receiving an authorization request for a payment transaction, the request including an account identifier, location identifier, and authorization time; identifying a specific data entry where the included time is within a predetermined period of time of the authorization time; when the location included in the specific data entry is indicative of the mobile device being not present at the location of the location identifier, transmitting a request to a computing device associated with the account identifier for action by a user to prove their identity; receiving, data conveying the action taken by the user; and authenticating the user based on the received data and authentication information associated with a payment account corresponding to the account identifier.