Approaches presented herein enable challenge-response authentication of a user based on information captured by a personal internet of things (IoT) device set associated with the user. Specifically, in one approach, a personal IoT device set comprising at least one device records and stores data associated with a user. The data is synchronized and stored to a computerized authentication system, which prompts the user with an authentication question based on the synchronized and stored data. The user may find an answer to the authentication question by reviewing data recorded and stored in the device of the personal IoT device set. The user may then enter the found answer to the authentication question, thereby authenticating the user. The personal IoT device set may comprise a single device or may comprise a plurality of devices, the information of one of which may be selected as the basis of the authentication question.