Massive data is written to blockchain systems for the destination of keeping safe. However, existing blockchain protocols still demand that each full node has to contain the entire chain. Most nodes quit because they are unable to grow their storage space with the size of data. As the number of nodes decreases, the security of blockchains would significantly reduce. We present SE-Chain, a novel scale-out blockchain model that improves storage scalability under the premise of ensuring safety and achieves efficient retrieval. The SE-Chain consists of three parts: the data layer, the processing layer and the storage layer. In the data layer, each transaction is stored in the AB-M tree (Adaptive Balanced Merkle tree), which adaptively combines the advantages of balanced binary tree (quick retrieval) and Merkle tree (quick verification). In the processing layer, the full nodes store the part of the complete chain selected by the duplicate ratio regulation algorithm. Meanwhile, the node reliability verification method is used for increasing the stability of full nodes and reducing the risk of imperfect data recovering caused by the reduction of duplicate number in the storage layer. The experimental results on real datasets show that the query time of SE-Chain based on the AB-M tree is reduced by 17% when 16 nodes exist. Overall, SE-Chain improves the storage scalability extremely and implements efficient querying of transactions.

海量数据被写入区块链系统，以确保安全。然而，现有的区块链协议仍然要求每个完整节点必须包含整个链。大多数节点退出是因为它们无法随着数据的大小增加存储空间。随着节点数量的减少，区块链的安全性会显着降低。我们提出SE-Chain，一种新的横向扩展区块链模型，它在确保安全的前提下提高存储可扩展性并实现高效检索。SE-Chain由三部分组成：数据层、处理层和存储层。在数据层，每笔交易都存储在AB-M树（Adaptive Balanced Merkle tree）中，自适应地结合了平衡二叉树（快速检索）和Merkle树（快速验证）的优点。在处理层，全节点存储通过重复比例调节算法选择的完整链的部分。同时，采用节点可靠性验证方法，提高全节点的稳定性，降低存储层重复数减少导致数据恢复不完善的风险。在真实数据集上的实验结果表明，当存在 16 个节点时，基于 AB-M 树的 SE-Chain 查询时间减少了 17%。总体而言，SE-Chain极大地提高了存储的可扩展性，实现了高效的交易查询。节点可靠性验证方法用于增加全节点的稳定性，降低存储层减少重复数导致数据恢复不完善的风险。在真实数据集上的实验结果表明，当存在 16 个节点时，基于 AB-M 树的 SE-Chain 查询时间减少了 17%。总体而言，SE-Chain极大地提高了存储的可扩展性，实现了高效的交易查询。节点可靠性验证方法用于增加全节点的稳定性，降低存储层减少重复数导致数据恢复不完善的风险。在真实数据集上的实验结果表明，当存在 16 个节点时，基于 AB-M 树的 SE-Chain 查询时间减少了 17%。总体而言，SE-Chain极大地提高了存储的可扩展性，实现了高效的交易查询。