Proposal of MQTT-based Micropayment System <Abstract> With the increase of IoT devices and their sensing data, the demand for IoT data sharing methods has recently increased. The IoT data, normally collected by low-resource IoT devices, is small in volume. It is hence expected to transmit and utilize the data efficiently. To this end, transfer data in exchange for small electronic payments called micropayments will be a good solution. The micropayment for small amounts of IoT data needs to support many transactions with low latency and low fees. The previous work had proposed a P2P micropayment system for IoT. However, that system uses Transport Control Protocol (TCP) to exchange data, limiting to a one-to-on communication. In this work, we propose an MQTT-based micropayment system, which allows multiple IoT devices to perform simultaneous transactions. The micropayment system uses the distributed ledger technology/cryptocurrency called IOTA, which can speed transactions without fees. |