Abstract: Nowadays, the maximum storage capacity of blockchain is limited to the node with the minimum storage capacity in the entire network. This paper presents a scalable model for storage capacity of blockchain, which fragments a blockchian replica and stores the fragments in a part of nodes. This model adds verification nodes to blockchian system. These nodes can detect and update the storage nodes stability by using the POR (proofs of retrievability) method in real time. Thus, the model records the stability values and chooses the high stability nodes to store the copies of the blocks. Finally, under the conditions of normal running, node failure and malicious attack on multiple nodes, the experimental results on real datasets show that the scalable model not only has stability, fault tolerance and safety, but also reduces the amount of storage space.

Key words:  blockchains, storage scalability, data replication, verification nodes, proofs of retrievability

摘要： 目前区块链的容量受到网络里存储空间最小的节点的限制，提出了区块链存储容量可扩展模型，该模型将一条完整的区块链副本进行分片处理，并将分片数据保存在一定比例的节点中。同时，模型增加了验证节点，对存储数据的节点进行基于数据可检索性证明（proofs of retrievability，POR）方法的实时检测，并记录更新存储节点稳定性值，依此选择高稳定性节点来储存新产生的数据副本，提高了数据存储的稳定性。最后，模型在多节点中正常运行、节点故障和有恶意攻击时的实验表明，区块链存储容量可扩展模型在具有稳定性、容错性和安全性的同时，有效地增加了区块链的存储扩展性。

关键词: 区块链, 储存扩展性, 数据副本, 验证节点, 可检索性证明