摘要
针对基于传统区块链进行医疗数据共享时可扩展性受限制的问题,提出一种基于分片技术的区块链扩容共享方案。首先,基于跳跃一致性哈希算法进行周期性网络分片,通过随机划分全网节点大幅度降低单分片内女巫攻击的风险;其次,分片内使用可扩展的去中心化信任基础设施区块链(SBFT)共识协议以降低实用拜占庭容错(PBFT)共识协议的高通信复杂度,并且在分片的物理多链与主链的逻辑单链间采用双层架构以减小分片成员的存储压力;最后,在医疗联盟链上提出基于公钥密码体制的多关键词关联检索可搜索加密共享方案(PECKS),从而提高病人对自己敏感数据的掌控度,并实现加密情况下敏感数据的细粒度检索。通过性能分析可以看出,在并行分片结构下,区块链吞吐量随分片增加有明显增长,检索效率也得到显著提升。实验结果表明,所提方案能大幅度提升区块链系统的效率与可扩展性。
Aiming at the limited scalability of medical data sharing based on traditional blockchains,a scale-out and sharing scheme of blockchain based on sharding technology was proposed.Firstly,the periodic network sharding was performed based on the jump consistent hash algorithm,and the risk of Sybil attacks in a single shard was greatly reduced by randomly dividing the network nodes.Then,the Scalable decentralized Trust inFrastructure for Blockchains(SBFT)consensus protocol was used in the shards to reduce the high communication complexity of the Pratic Byzantic Fault Torent(PBFT)consensus protocol,and the two-layer architecture was used between the physical multi-chain of shards and the logical single chain of the main chain to reduce the storage pressure of the members of shards.Finally,a multi-keyword association retrieval searchable encryption sharing scheme based on Public key Encryption with Conjunctive field Keyword Search(PECKS)was proposed on the medical consortium blockchain,so as to improve the patients’control over their sensitive data,and realize the fine-grained search of sensitive data under encryption.Through performance analysis,it can be seen that under the parallel sharding structure,the throughput of blockchain is significantly increased with the increase of shards,and the retrieval efficiency is also significantly improved.Experimental results show that the proposed scheme can greatly improve the efficiency and scalability of the blockchain system.
作者
李莉
吴怡
杨祉坤
陈云鹏
LI Li;WU Yi;YANG Zhikun;CHEN Yunpeng(College of Information and Computer Engineering,Northeast Forestry University,Harbin Heilongjiang 150040,China)
出处
《计算机应用》
CSCD
北大核心
2022年第1期183-190,共8页
journal of Computer Applications
关键词
区块链
分片技术
共识协议
医疗电子病历
可搜索加密
数据共享
blockchain
sharding technology
consensus protocol
Medical Electronic Record(MER)
searchable encryption
data sharing
