Embodiments of the present disclosure provide a method and system for guided implicit authentication. The system first receives a request to access the controlled resource from a user. The system then determines whether the user request is inconsistent with regular user behavior by calculating a user behavior measure derived from historical contextual data of past user events. Next, the system allows the user to provide information associated with regular user behavior and/or current contextual data. The system further updates the user behavior measure based on current contextual data.