From the abstract:

Device, system, and method of managing trustworthiness of electronic devices. For example, an Internet of Things (IoT) device is able to transmit data to a recipient device. The recipient device operates as a querying device, and utilizes a query agent to query a trust-management server with regard to the trustworthiness of the IoT device. The trust-management server receives from the IoT device a set of values indicating various parameters of the IoT device. The trust-management server generates a trustworthiness report pertaining to the IoT device, and sends the report as a response to the trustworthiness query. Optionally, a caching agent caches copies of trustworthiness reports and provides to querying devices such previous reports, together with an indication of their freshness level.