区块链增强型轻量级节点模型

区块链固有的链式结构意味着其数据量无休止地线性增长，随着时间的积累，对单个节点的存储造成很大的压力，对整个系统的存储空间造成极大的浪费。在比特币白皮书中提出的SPV（Simplified Payment Verification）节点模型，大大减少节点对存储空间的需求，但是，它使得全节点的个数减少、压力增大，减弱了整个系统的去中心化程度，存在拒绝服务攻击、女巫攻击等安全隐患。通过对比特币区块数据进行分析，提出一种功能完整的增强型轻量级节点模型ESPV（Enhanced SPV）。ESPV把区块分为新区块和旧区块，对它们采用不同的存储管理策略。新区块以全部副本（每个节点保存一份）的方式保存以用于交易验证，用较少的存储空间代价让ESPV具有交易验证（挖矿）功能；旧区块分片存储在网络的节点中，通过分级区块分区路由表访问，在保证数据可用性和可靠性的前提下减少系统对存储空间的浪费。ESPV节点具有完整的节点功能，从而保证区块链系统的去中心化特性，增强其安全性和稳定性。实验结果表明，ESPV节点具有80%以上的交易验证率，在数据量和增长量上这些节点仅为全节点的10%，ESPV的数据可用性和可靠性有保障，适用于系统的整个生命周期。

Blockchain enhanced lightweight node model

The inherent chain structure of blockchain means that its data volume grows linearly and endlessly. Over time,it causes a lot of pressure on the storage of the single node,which greatly wastes the storage space of the whole system. The Simplified Payment Verification(SPV)node model proposed in the Bitcoin white paper greatly reduces the node's need for storage space. However,it reduces the number of nodes and increases the pressure,which weakens the decentralization of the entire system and has security risks such as denial of service attacks and witch attacks. By analyzing the Bitcoin block data,a fully functional enhanced lightweight node model Enhanced SPV(ESPV)was proposed. The block was divided into new blocks and old blocks by ESPV,and different storage management strategies were adopted for them. The new block was saved in full copy(one copy per node)for transaction verification,allowing ESPV to has transaction verification(mining) function with less storage space cost. The old block was stored in the nodes of the network in slices,and was accessed through the hierarchical block partition routing table,thereby reducing the waste of the storage space of the system under the premise of ensuring data availability and reliability. The ESPV nodes have full node functionality,thus ensuring the decentralization of the blockchain system and enhancing the security and stability of the system. The experimental results show that the ESPV nodes have more than 80% transaction verification rate,and the data volume and growth amount of these nodes are only 10% of those of all nodes. The data availability and reliability of ESPV are guaranteed,and it is applicable to the whole life cycle of the system.