Confidential discovery of IoT devices through blockchain

Selection criteria regulating IoT device discovery involve confidentiality issue on the information the constraints convey. A promising approach to cope with this issue is leveraging on blockchain technology and smart contracts to implement the overall discovery process deployment. However, due to the blockchain design, data within the blockchain is public and smart contracts cannot access data outside the blockchain, unless through the exploitation of Oracles. On the one hand, this brings benefits of trust decentralization, transparency, and accountability of the discovery process. On the other hand, it carries serious consequences on confidentiality and privacy as well as on Oracles trustworthiness. For these reasons, in this paper, we investigate how to ensure data confidentiality during the discovery process of IoT devices on blockchain even in the presence of an untrusted Oracle.