Systems, methods, routines and/or techniques for limiting the functionality of a software program based on a security model are described. One or more embodiments may include limiting the functionality of a software program (e.g., a widget) based on one or more operations that the widget intends to take. One or more embodiments may include limiting the functionality of a widget that is located on and/or accessible via a lock screen of a mobile device. One or more embodiments may include preventing a widget from causing an application to perform sensitive actions when a system is in an un-authenticated state. One or more embodiments may include preventing a widget from installing and/or displaying on a particular screen of a mobile device (e.g., a lock screen) if the widget includes a function that indicates that a sensitive operation will be taken.