Abstract: Technology for establishing trustworthiness of devices in the Internet of Things (IoT), and for controlling communications between devices based on the trustworthiness scores of individual devices. A hub computer collects behavioral characteristics from multiple devices, and calculates trustworthiness scores for individual devices by comparing recently collected behavioral characteristics to expected behavioral characteristics. The expected behavioral characteristics may include i) historically collected behavioral characteristics for the device, and/or ii) expected behavioral characteristics for devices in a device group to which the device belongs. The trustworthiness scores are obtained from the hub by individual devices to control communication with other devices. A composite trustworthiness score for a device may also be calculated at the hub computer based on the trustworthiness scores of other devices with which the device has previously communicated.