A Hybrid Storage Scheme for Improving the Scalability of Bitcoin Network Based on IPFS

Till the end of September 2021, the size of Bitcoin blockchain has reached 366.9GB and continues to increase at an average annual growth rate of 17.6%. The high requirement for storage space prevents new nodes from joining the network, which seriously hinders the development of blockchain technology. In this paper, in order to explore the data characteristics of Bitcoin's block, we performed statistical experiment on the current 680,000 blocks. The analysis results showed that in nearly 95% of blocks, the number of spent transaction output(STXO) accounts for more than 67% of the total transaction output. Inspired by this, we proposed a hybrid storage scheme to reduce the size of blocks by deleting the transaction data with the STXO ratio over 67% firstly and compressing some fixed-length fields in those transactions. And then, the newly generated block files were deposited to the InterPlanetary File System(IPFS) private network to improve the scalability of Bitcoin network. The experiment results and analysis showed that our scheme achieved a compression ratio of 96.9% and could effectively help the Bitcoin full nodes save 330GB of storage space with guaranteeing the normal operation of Bitcoin network.