A Scalable Storage Scheme for On-Chain Big Data using Historical Blockchains

Despite the growing interest in blockchain technology, the scalability of blockchain storage has become a major issue for applications that require large amounts of on-chain data. In this paper, we propose a novel scalable storage scheme for consortium networks to manage the storage capacity required by data-rich blockchain applications. We establish network nodes as super peers or regular peers, where super peers can maintain old blockchain data in the form of historical blockchains. Regular peers maintain only the latest blockchain data stored in the current blockchain, but they can access any data in the historical blockchains by making queries to the super peers. We present procedures to build a historical blockchain and retrieve data from the historical blockchains and the current blockchain in a concurrent manner. Experimental results show that our scalable storage scheme using historical blockchains is feasible and effective in accessing and sharing healthcare data with image files.