ElasticChain: Support Very Large Blockchain by Reducing Data Redundancy

Dayu Jia, Junchang Xin, Zhiqiong Wang, Wei Guo, Guoren Wang

Abstract: Blockchains are secure by design and they have been widely used in digital asses, trade finance, information security and many other fields. However, the current blockchain protocol requires that each full node must contain the complete chain. When the storage capacity of a full node is less than that of the complete chain, this node cannot be a member of blockchain system. With the input data increasing, the number of full nodes in blockchains would decrease. The security of blockchains would significantly reduce. Therefore, we provide the ElasticChain, which can improve storage scalability under the premise of ensuring blockchain data safety. The full nodes in ElasticChain store the part of the complete chain based on the duplicate ratio regulation algorithm. Meanwhile, the node reliability verification method was used for increasing the stability of full nodes and reducing the risk of data imperfect recovering caused by the reduction of duplicate number. The experimental results on real datasets show that ElasticChain has the same stability, fault tolerance and security with the current blockchain system and it improves the storage scalability extremely.