A method and system for determining user security is provided. The method includes registering a first user associated with a service provider system by retrieving identification information for the first user and a first user communication device. In response, Internet of things (IOT) devices belonging to the first user are detected. A second user associated with the service provider system is registered by retrieving identification information for the second user and a second user communication device. In response, IOT devices belonging to the second user are detected. A request for a service provided by the service provider system is received from the first user via the first user communication device belonging to the first user.