Secure and Efficient Web of Things Digital Twins using Permissioned Blockchains

The growing popularity and features of digital twins have made them key elements in Industry 4.0 and the Internet of Things (IoT). In this paper, we propose the use of digital twins as an indirection mechanism, instead of accessing directly the actual IoT devices, in order to offer secure sensing and actuation in IoT systems through Distributed Ledger Technologies (DLTs), which can enhance the security and transparency of such digital twins. In particular, we leverage advances in Web of Things (WoT) and permissioned blockchains to build flexible and secure digital twins. Specifically, we build smart contract-based digital twins of IoT devices that follow W3C's WoT standards. This architecture offers decentralization, immutability, auditability, and enhanced availability and reliability.