Method comprising: storing, in a digital security delivery database , information about a user that is enrolled in push notification authentication, the information about the user (760, ... ) including hardware characteristics of a mobile device ; receiving , at an application programming interface (API) framework coupled to a communication interface and to the digital security delivery database (754, ... ), a request from a service provider system to create an authentication task for a transaction requiring push notification authentication; transmitting , from the APIframework (751, ...) to a database management system , a generic notification that a particular authentication task requires push notification authentication; transmitting , from the database management system , a push notification to the mobile device (130, ...); receiving , at the APIframework (751, ...) a request from the mobile device (130, ...) to retrieve the authentication task associated with the push notification, the request including the information about the user and the hardware characteristics of the mobile device (130, ...); transmitting , from the API framework (751, ...), after validating the received hardware characteristics of the mobile device, the authentication task to the mobile device (130, ...); receiving , at the API framework (751, ...) from the mobile device (130, ...), information indicating that the transaction requiring push notification authentication has been approved by the user (760, ...) of the mobile device (130, ...); updating , by the API framework (751, ...), the digital security delivery database (754, ...) to indicate that the transaction requiring push notification authentication has been approved by the user (760, ...); and notifying , by the API framework (751, ...), the service provider system that the transaction requiring push notification authentication has been approved. storing, in a digital security delivery database , information about a user that is enrolled in push notification authentication, the information about the user (760, ... ) including hardware characteristics of a mobile device ; receiving , at an application programming interface (API) framework coupled to a communication interface and to the digital security delivery database (754, ... ), a request from a service provider system to create an authentication task for a transaction requiring push notification authentication; transmitting , from the APIframework (751, ...) to a database management system , a generic notification that a particular authentication task requires push notification authentication; transmitting , from the database management system , a push notification to the mobile device (130, ...); receiving , at the APIframework (751, ...) a request from the mobile device (130, ...) to retrieve the authentication task associated with the push notification, the request including the information about the user and the hardware characteristics of the mobile device (130, ...); transmitting , from the API framework (751, ...), after validating the received hardware characteristics of the mobile device, the authentication task to the mobile device (130, ...); receiving , at the API framework (751, ...) from the mobile device (130, ...), information indicating that the transaction requiring push notification authentication has been approved by the user (760, ...) of the mobile device (130, ...); updating , by the API framework (751, ...), the digital security delivery database (754, ...) to indicate that the transaction requiring push notification authentication has been approved by the user (760, ...); and notifying , by the API framework (751, ...), the service provider system that the transaction requiring push notification authentication has been approved. <EOS>