医疗区块链系统的用户向全节点请求数据时可能被欺骗，而简单支付验证等轻节点数据查询方法面临着存储困难。为解决这些问题，提出了一种面向医疗区块链的新型轻节点数据查询方法。引入具有动态追加能力的Merkle山脉（Merkle mountain range,MMR），设计基于推荐的可信节点选择和基于采样的可信节点验证的最新有效块获取算法，采取MMR和Merkle树的承诺机制，使得持有一个最新有效块的轻节点用户能够验证全节点发送的医疗数据。此外，还将该方法扩展应用于联盟链。分析和实验表明，所提方法的时间开销和空间开销均在较低的范围内。
In medical blockchain systems, users may be cheated by whole node when they request data from the whole node. Meanwhile, owing to the lack of storage, simple payment verification (SPV) and other verification methods of light node data are not applicable to medical blockchain systems. In order to solve these problems, this paper proposes a new light node data query method for medical blockchains. In the proposed method, the Merkle mountain range (MMR) with dynamic addition capability is introduced, and the latest valid block query algorithm based on recommendation trusted node selection and trusted node verification on sampling is designed. Accordingly, by using the commitment mechanism of the MMR and Merkle tree, the medical data sent by the whole node are verified by the user of the light node which holds the latest valid block obtained from a trusted node. Furthermore, the proposed method can be extended to the application of consortium blockchains. Analysis and experiments on the proposed method show that both time cost and space cost are in low overhead ranges.
[1] 李姝,赵培培,于金刚,等.基于区块链的数据交易平台的研究与设计[J].小型微型计算机系统, 2021, 42(5):1109-1114.Li S, Zhao P P, Yu J G, et al.Research and design of data trading platform based on blockchain[J].Journal of Chinese Mini-Micro Computer Systems, 2021, 42(5):1109-1114.(in Chinese)
[2] Reyna A, Martín C, Chen J, et al.On blockchain and its integration with IoT challenges and opportunities[J].Future Generation Computer Systems, 2018, 88:173-190.
[3] 蔡维德,郁莲,王荣,等.基于区块链的应用系统开发方法研究[J].软件学报, 2017, 28(6):1474-1487.Tsai W T, Yu L, Wang R, et al.Blockchain application development techniques[J].Journal of Software, 2017, 28(6):1474-1487.(in Chinese)
[4] Bonneau J, Miller A, Clark J, et al.Sok:research perspectives and challenges for bitcoin and cryptocurrencies[C]//2015 IEEE Symposium on Security and Privacy, 2015:104-121.
[5] Cheng J, Song J, Fan D, et al.Current status and prospects of blockchain technology[C]//International Conference on Artificial Intelligence and Security, 2020:674-684.
[6] Merkle R C.Protocols for public key cryptosystems[C]//1980 IEEE Symposium on Security and Privacy, 1980:122-122.
[7] 韩璇,袁勇,王飞跃.区块链安全问题:研究现状与展望[J].自动化学报, 2019, 45(1):206-225.Han X, Yuan Y, Wang F Y.Security problems on blockchain:the state of the art and future trends[J].Acta Automatica Sinica, 2019, 45(1):206-225.(in Chinese)
[8] Nakamoto S.Bitcoin:a peer-to-peer electronic cash system[R/OL].(2008-10-31)[2021-06-11].https://www.debr.io/article/21260-bitcoin-a-peer-to-peer-electronic-cash-system.
[9] Todd P.Merkle mountain range[EB/OL].(2018-12-20)[2021-04-29].https://github.com/opentimestamps/opentimestamps-server/blob/master/doc/merkle-mountain-range.md.
[10] Liu J, Li X, Ye L, et al.BPDS:a blockchain based privacy-preserving data sharing for electronic medical records[C]//2018 IEEE Global Communications Conference, 2018:1-6.
[11] Yang X, Li T, Pei X, et al.Medical data sharing scheme based on attribute cryptosystem and blockchain technology[J].IEEE Access, 2020, 8:45468-45476.
[12] Cao S, Zhang G, Liu P, et al.Cloud-assisted secure eHealth systems for tamper-proofing EHR via blockchain[J].Information Sciences, 2019, 485:427-440.
[13] 张超,李强,陈子豪,等.Medical chain:联盟式医疗区块链系统[J].自动化学报, 2019, 45(8):1495-1510.Zhang C, Li Q, Chen Z H, et al.Medical Chain:alliance medical blockchain system[J].Acta Automatica Sinica, 2019, 45(8):1495-1510.(in Chinese)
[14] Bünz B, Kiffer L, Luu L, et al.Flyclient:super-light clients for cryptocurrencies[C]//2020 IEEE Symposium on Security and Privacy, 2020:928-946.
[15] 张学旺,冯家琦,殷梓杰,等.基于区块链的数据溯源可信查询方法[J].应用科学学报, 2021, 39(1):42-54.Zhang X W, Feng J Q, Yin Z J, et al.Trusted query method for data provenance based on blockchain[J].Journal of Applied Sciences, 2021, 39(1):42-54.(in Chinese)
[16] Benet J.IPFS-content addressed, versioned, P2P file system[J/OL].arXiv preprint arXiv:1407.3561, 2014.(2014-07-14)[2022-06-11].https://arxiv.org/abs/1407.3561.
