Abstract: Blockchain has the characteristics of decentralization and immutability, and has received widespread attention in recent years. Data can not be tampered, which will cause a series of problems such that malicious transactions can not be eradicated and wrong transactions can not be modified. The existing related researches can modify specific block data, or add new transactions to achieve logical editing. The former will cause the editing record can not be verified, the latter can keep the wrong data storage, but lack of secure access mechanism. In addition, the existing relevant studies have not fully considered the characteristics of the data to be edited, resulting in subsequent transactions affected and ineffective. Therefore, an editable blockchain model is proposed. Firstly, taking deposit data as an example, the underlying data structure of blockchain is redesigned, time-series attributes are added, and the index is built. Then it proposes new submission, editing and query algorithms, and realizes the logical editing of blockchain data through subsequent additional transactions, to provide users with a secure access interface on the basis of saving the wrong transaction certificate. Finally, based on the above work, the data structure and algorithms of transaction data are improved to solve the problem of subsequent transaction failure, to ensure that subsequent transactions are not affected by data editing. Experimental results show that this model can realize the editable blockchain on the basis of ensuring performance of the system.

Key words: blockchain, editable, temporal index, history query

摘要： 区块链具有去中心化与不可篡改等特点，近年来受到了人们广泛的关注。数据上链便不可篡改会带来恶意交易无法根除和错误交易无法修改等一系列问题。目前可编辑区块链的相关研究大多是以区块粒度进行替换，或者通过增添新交易实现逻辑上的编辑。前者会造成编辑记录无法考证，后者虽可保留错误数据存证，但缺乏安全的访问机制。此外，现有相关研究均未充分考虑待编辑数据的特点，导致后续交易受影响而失效的问题。因此，提出了一种可编辑区块链模型。首先，以一般存证数据为例，重新设计了区块链底层数据结构，增加了时序属性并构建索引；然后提出了新的提交、编辑和查询算法，通过后续追加交易的方式实现了对区块链数据的逻辑编辑，从而在保存错误交易存证的基础上，为用户提供了安全的访问接口。为了解决后续交易失效的问题，在上述工作基础上，针对上下文强相关的交易类型数据，对数据结构及相关算法进行了改进，保证后续交易不受数据编辑的影响。实验表明，该模型可在保证系统性能的基础上实现区块链可编辑。

关键词: 区块链, 可编辑, 时序索引, 历史查询