Examples described herein relate to a blockchain Internet-of-Things (IoT) system. The blockchain IoT system include a blockchain IoT device that generates event data and attests the event data using a decentralized identity provisioned to the blockchain IoT device. The blockchain IoT system further includes a blockchain network coupled to the blockchain IoT device via a network. The blockchain network includes a blockchain IoT management sub-system to receive the event data from the blockchain IoT device, verify the decentralized identity associated with the blockchain IoT device, and upon successful verification of the decentralized identity, process the event data. The blockchain network also includes a blockchain ledger sub-system to verify the processed event data and, upon successful verification of the processed event data, store the processed event data in a distributed ledger.