Serving at the edge: A redactable blockchain with fixed storage

Abstract

As a promising approach to extend cloud resource and service on the Internet-of-Things (IoT), edge computing has attracted significant attention. However, edge computing faces challenges in its decentralized management and data reliability. To meet this gap, many approaches propose to use blockchain technology to enable distributed storage and computation at the edge nodes, thus guaranteeing reliable access and control of the network. However, the resource-constraint nature of the edge node makes it difficult to store the entire chain as the data volume increases. To address this issue, we propose Re-chain, a re-writable blockchain with fixed storage. Re-chain supports re-writing of the onchain historical transactions in chronological order without changing the block hash, as a result, the total size of the blockchain will not increase. Our protocol is consensus-based and uses the proposed threshold trapdoor chameleon hash (TTCH) to constraint re-write operations. With this regards, Re-chain achieves both decentralized re-writing design and fault-tolerance at the same time. We provide security analysis and evaluation experiments to demonstrate the feasibility of Re-chain, the results show that the performance of Re-chain is acceptable when it is executed at a medium scale.