Abstract:With the rapid development of the blockchain, the data on the chain not only include financial data, but also have data of technology, culture, politics, and so on. However, the data will not be revised once it is packaged on the existing blockchain system, which has the problem that the invalid data cannot be deleted and the wrong data cannot be modified. Therefore, a revisable blockchain under certain conditions has broad application prospects. Under the POSpace (proof of space) consensus mechanism, a revisable blockchain scheme is proposed based on the trapdoor one-way function and a new blockchain structure. In this scheme, the nodes can execute the revision operation as long as their number exceeds the threshold. Otherwise, the revision operation cannot be executed. Except for the revised data, the remaining data on the blocks keeps unchanged, and all of the nodes on the network can still verify the validity of data by using the original verification ways. The experiments show that block generation and data revision all have high efficiency as long as the threshold is selected appropriately, and the link relationship between the blocks will not be changed after the data revision, and the scheme has practical operability.