可修改的区块链方案

Scheme of Revisable Blockchain

随着区块链的迅速发展,上链数据不仅包括金融交易数据,还包括科技、文化、政治等多类数据.而在现有的区块链系统中,数据一旦上链便无法更改,可能会面临失效数据无法删除、错误数据无法修改等问题.因此,特定条件下可修改的区块链方案具有广阔的应用前景.在POSpace(proof of space)共识机制下,基于陷门单向函数和新型区块链结构,提出了可修改的区块链方案.只要超过阈值数的节点同意,便可实现区块数据的合法修改,否则不能进行修改.除修改数据外,其余区块数据保持不变,全网节点仍可按原始验证方式对数据合法性进行验证.仿真实验表明:只要选定合适的阈值,所提方案中,区块生成与数据修改的效率均很高,数据的修改并不改变区块之间的链接关系,具有现实可操作性.

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.