Performance Evaluation of Blockchains Towards Sharing of Digital Twins.

Citizens need to be involved to construct digital twins by sensing the urban environments using their IoT devices and sharing the sensed data among application providers. This "cooperative sensing" is one of the key solutions to achieve sustainable smart cities/super cities and offers improvement of the Quality of Life of citizens. In this view, blockchain and distributed ledger technology are collecting much attention to build a distributed data exchanging/sharing system for IoT data as well as cryptocurrency. However, the blockchain has a scalability issue in terms of large data volume and high-frequency transaction cases. In this paper, in order to reveal the comprehensive performance of blockchain when it is applied to sensor data sharing, we build a data-sharing system using Hyperledger Fabric which is one of the well-known blockchain platforms and evaluate the system performance by using a variety of sensing data, including images and 3D objects.