Principle and Core Technology of Blockchain

doi:10.3778/j.issn.1673-9418.2004029

Abstract

Abstract:

Blockchain is a kind of technology which comprehensively uses cryptography, distributed databases, P2P communication, smart contracts and other technologies. In a decentralized and trustless network, it uses encryption algorithms to verify and store data in a chained data structure. Blockchain technology is a universal low-level technical architecture that generates and synchronizes data on distributed nodes through a consensus mechanism, and implements automatic execution of contract terms and data operations with the help of programmable scripts. This paper systematically sorts out the blockchain and deconstructs its key technical elements. Under this premise, the basic architecture of the blockchain system is analyzed starting from the architecture and the implementation protocol. Taking the application development of blockchain technology as the context and combining with the application scenarios of Bitcoin, Ethereum and Super Ledger, the technical principles, implementation paths, app-lication status and existing challenges are expounded. This paper seeks to provide readers with help and reference in the systematic learning and in-depth research of blockchain technology.

Key words: blockchain, Bitcoin, Ethereum, consensus mechanism, encryption algorithm, smart contract

摘要：

区块链是综合运用密码学、分布式数据库、P2P通信、智能合约等的技术，在一个去中心化、去信任网络中，利用加密算法在链式数据结构中验证和存储数据。区块链技术是一项具有普适性的底层技术架构，它通过共识机制在分布式节点上生成和同步数据，借助可编程脚本实现合约条款的自动执行和数据操作。对区块链进行系统梳理并对其关键技术元素进行解构，在此前提下，从体系结构和实现协议入手分析了区块链系统的基础架构，以区块链技术的应用发展为脉络，主要结合比特币、以太坊和超级账本应用场景，对其技术原理、实现路径、应用现状和存在的挑战进行了阐述。力求为读者在系统学习区块链技术的基础上致力于更深入的研究提供帮助和借鉴。

关键词: 区块链, 比特币, 以太坊, 共识机制, 加密算法, 智能合约

WANG Qun, LI Fujuan, WANG Zhenli, LIANG Guangjun, XU Jie. Principle and Core Technology of Blockchain[J]. Journal of Frontiers of Computer Science and Technology, 2020, 14(10): 1621-1643.

王群，李馥娟，王振力，梁广俊，徐杰. 区块链原理及关键技术[J]. 计算机科学与探索, 2020, 14(10): 1621-1643.

References

[1] Nakamoto S. Bitcoin: a peer-to-peer electronic cash system[EB/OL]. (2018-06-10)[2020-03-10]. https://bitcoin.org/bitcoin.pdf.
[2] Buterin V. A next-generation smart contract and decentralized application platform (white paper)[EB/OL]. (2019-06-17)[2020-03-10]. https://github.com/ethereum/wiki/wiki/White-Paper.
[3] Underwood S. Blockchain beyond bitcoin[J]. Communications of the ACM, 2016, 59(11): 15-17.
[4] Kyle C, Christian D, Ittay E, et al. On scaling decentralized blockchains[C]//Proceedings of the 2016 International Con-ference on Financial Cryptography and Data Security, Bar-bados, Feb 26, 2016. Berlin, Heidelberg: Springer, 2016: 106-125.
[5] Dorri A, Steger M, Kanhere S S, et al. BlockChain: a distri-buted solution to automotive security and privacy[J]. IEEE Communications Magazine, 2017, 55(12): 119-125.
[6] Wang S, Yuan Y, Member S, et al. An overview of smart con-tract: architecture, applications, and future trends[C]//Pro-ceedings of the 2018 IEEE Intelligent Vehicles Symposium,Changshu, Jun 26-30, 2018. Piscataway: IEEE, 2018: 108-113.
[7] Shao Q F, Jin C Q, Zhang Z, et al. Blockchain: architecture and research progress[J]. Chinese Journal of Computers, 2018, 41(5): 969-988. 邵奇峰, 金澈清, 张召, 等. 区块链技术: 架构及进展[J]. 计算机学报, 2018, 41(5): 969-988.
[8] Yuan Y, Wang F Y. Blockchain: the state of the art and future trends[J]. Acta Automatica Sinica, 2016, 42(4): 481-494. 袁勇, 王飞跃. 区块链技术发展现状与展望[J]. 自动化学报, 2016, 42(4): 481-494.
[9] King S, Nadal S. PPCoin: peer-to-peer crypto-currency with proof-of-stake[EB/OL]. (2015-09-13)[2020-03-19]. https://www.peercoin.net/assets/paper/peercoin-paper-nl.pdf.
[10] Wright M. Delegated proof of stake (DPOS) vs proof of work (POW)[EB/OL]. (2015-01-04)[2020-07-08]. http://bytemaster.github.io/bitshares/2015/01/04/Delegated-Proof-of-Stake-vs- Proof-of-Work/.
[11] Szabo N. Smart contracts[EB/OL]. (1994-06-10)[2020-03-19]. http://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/smart.contracts.html.
[12] Cai W, Wang Z, Ernst J B, et al. Decentralized applications: the blockchain-empowered software system[J]. IEEE Access, 2018, 6: 53019-53033.
[13] Zheng Z B, Xie S A, Dai H N, et al. An overview of block-chain technology: architecture, consensus, and future trends[C]//Proceedings of the 6th IEEE International Congress on Big Data, Honolulu, Jun 25-30, 2017. Piscataway: IEEE, 2017: 557-564.
[14] Sompolinsky Y, Zohar A. Secure high-rate transaction pro-cessing in bitcoin[EB/OL]. (2017-10-22)[2020-03-20]. https://eprint.iacr.org/2013/881.pdf.
[15] Sompolinsky Y, Zohar A. Accelerating bitcoin??s transaction processing fast money grows on trees, not chains[EB/OL]. (2014-01-01)[2020-03-20]. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.433.6590&rep=rep1&type=pdf.
[16] Merkle R C. A certified digital signature[C]//Proceedings of the Advances in Cryptology, Santa Barbara, Aug 20-24, 1989. Berlin, Heidelberg: Springer, 1989: 218-238.
[17] Michael S. Merkle tree traversal in log space and time[C]//Proceedings of the Advances in Cryptology, Interlaken, May 2-6, 2004. Berlin, Heidelberg: Springer, 2004: 541-554.
[18] Dmitry M, Alexander C, Marc J. Short paper: revisiting difficulty control for blockchain systems[C]//LNCS 10436: Proceedings of the 2017 International Workshop on Data Privacy Management, Oslo, Sep 14-15, 2017. Berlin, Heidel-berg: Springer, 2017: 429-436.
[19] Morrison D R. PATRICIA-practical algorithm to retrieve information coded in alphanumeric[J]. Journal of the ACM, 1968, 15(4): 514-534.
[20] Antonopoulos A M. Mastering bitcoin: unlocking digital cryptocurrencies[M]. Sebastopol: O??Reilly Media, Inc., 2014.
[21] Vallois V, Guenane F A. Bitcoin transaction: from the creation to validation, a protocol overview[C]//Proceedings of the 2017 Cyber Security in Networking Conference, Rio de Janeiro, Oct 18-20, 2017. Piscacaway: IEEE, 2018: 63-69.
[22] Wikepedia. Berkeley DB[EB/OL]. (2019-05-14)[2020-03-26]. https://zh.wikipedia.org/wiki/Berkeley_DB.
[23] Ghemawat S, Dean F. LevelDB is a fast key-value storage library written at Google that provides an ordered mapping from string keys to string values[EB/OL]. (2011-08-10)[2020-03-26]. https://github.com/google/leveldb.
[24] Damien K, Jan L, Noah S, et al. CouchDB[EB/OL]. (2011-02-01)[2020-03-26]. https://www.immagic.com/eLibrary/ARCHIVES/GENERAL/WIKIPEDI/W110412C.pdf.
[25] Lamport L, Shostak R, Pease M. The Byzantine generals problem[J]. ACM Transactions on Programming Languages and Systems, 1982, 4(3): 382-401.
[26] Adam B. The Hashcash proof-of-work function(draft)[EB/OL]. (2003-06-01)[2020-06-27]. http://www.hashcash.org/papers/draft-hashcash.txt.
[27] Larimer D. Transactions as proof-of-stake[EB/OL]. (2013-11-28)[2020-03-10]. http://7fvhfe.com1.z0.glb.clouddn.com/wp-content/uploads/2014/01/TransactionsAsProofOfStake10.pdf.
[28] Bisola A. Delegated proof-of-stake (DPoS) explained[EB/OL]. (2018-11-01)[2020-03-10]. https://www.mycryptopedia.com/delegated-proof-stake-dpos-explained/.
[29] Fan J, Yi L T, Shu J W. Research on the technologies of Byzantine system[J]. Journal of Software, 2013, 24(6): 1346-1360. 范捷, 易乐天, 舒继武. 拜占庭系统技术研究综述[J]. 软件学报, 2013, 24(6): 1346-1360.
[30] Adam B. A partial hash collision based postage scheme[EB/OL]. (1997-03-28)[2020-03-27]. http://www.hashcash.org/papers/announce.txt.
[31] Bentov I, Lee C, Rosenfeld M, et al. Proof of activity: exte-nding bitcoin??s proof of work via proof of stake[J]. Perfor-mance Evaluation Review, 2014, 42(3): 34-37.
[32] Pavel V. BlackCoin??s proof-of-stake protocol v2[EB/OL]. (2016-06-01)[2020-03-28]. https://blackcoin.org/blackcoin-pos-protocol-v2-whitepaper.pdf.
[33] Schuh F, Larimer D. BITSHARES 2.0: financial smart con-tract platform[EB/OL]. (2015-11-01)[2020-03-29]. http://www.wenke99.com/p-427027.html.
[34] Lampson B W. How to build a highly available system using consensus[C]//LNCS 1151: Proceedings of the 1996 Interna-tional Workshop on Distributed Algorithms, Bologna, Oct 9-11, 1996. Berlin, Heidelberg: Springer, 1996: 1-17.
[35] Chao T W, Chung H, Kuo P C. Fair Byzantine agreements for blockchains[J]. arXiv:1907.03437, 2019.
[36] Wood T, Singh R, Venkataramani A, et al. ZZ and the art of practical BFT execution[C]//Proceedings of the 6th Confer-ence on Computer Systems, Salzburg, Apr 10-13, 2011. New York: ACM, 2011: 123-138.
[37] Hendricks J, Sinnamohideen S, Ganger G R, et al. Zzyzx: scalable fault tolerance through Byzantine locking[C]//Pro-ceedings of the 40th Annual IEEE/IFIP International Con-ference on Dependable Systems and Networks, Chicago, Jun 1-4, 2010. Piscataway: IEEE, 2010: 363-372.
[38] Dinh T T A, Wang J, Chen G, et al. BLOCKBENCH: a framework for analyzing private blockchains[C]//Procee-dings of the 2017 ACM International Conference on Mana-gement of Data, Chicago, May 14-19, 2017. New York: ACM, 2017: 1085-1100.
[39] Popejoy S. The pact programming language[EB/OL]. [2020-03-30]. https://www.ctolib.com/mip/pact.html.
[40] Dinh T T A, Liu R, Zhang M, et al. Untangling Blockchain: a data processing view of blockchain systems[J]. IEEE Tran-sactions on Knowledge and Data Engineering, 2018, 30(7): 1366-1385.
[41] Ethereum. Solidity[EB/OL]. (2016-01-01)[2020-03-30]. https://solidity.readthedocs.io/en/latest/.
[42] Ethereum. Serpent[EB/OL]. (2018-10-23)[2020-03-30]. https://github.com/ethereum/wiki/wiki/Serpent.
[43] Wikipedia. The DAO(organization)[EB/OL]. (2018-11-03)[2020-04-05]. https://en.wikipedia.org/wiki/The_DAO_organ-ization.
[44] Hyperledger. Hyperledger fabric[EB/OL]. (2020-04-02)[2020-04-07]. https://www.hyperledger.org/.
[45] Greg L, Test Z, Josh L, et al. EOS.IO technical white paper v2[EB/OL]. (2018-04-28)[2020-04-07]. https://github.com/EOSIO/Documentation/blob/master/TechnicalWhitePaper.md.
[46] Siraj R. Decentralized applications[M]. Sebastopol: O??Reilly Media, Inc., 2016.
[47] GitHub. Chaincode tutorials[EB/OL]. (2019-01-01)[2020-04-05]. https://hyperledger-fabric.readthedocs.io/en/release-1.4/chaincode.html.
[48] Fynn E, Pedone F. Challenges and pitfalls of partitioning blockchains[EB/OL]. (2018-05-09)[2020-04-05]. https://arxiv.org/pdf/1804.07356.pdf.
[49] Tong W, Dong X, Shen Y, et al. A hierarchical sharding protocol for multi-domain IoT blockchains[C]//Proceedings of the ICC 2019 IEEE International Conference on Com-munications, Shanghai, May 20-24, 2019. Piscataway: IEEE, 2019: 1-6.
[50] Zhang X, Ruizhen W U, Wang M, et al. A high-performance parallel computation hardware architecture in ASIC of SHA-256 hash[C]//Proceedings of the 21st International Conference on Advanced Communication Technology, PyeongChang, Feb 17-20, 2019. Piscataway: IEEE, 2019: 52-55.
[51] Yuan Q, Wei P, Jia K T, et al. Analysis of blockchain protocol against static adversarial miners corrupted by long delay atta-ckers[J]. Science China: Information Sciences (English), 2020(3): 45-59.
[52] Ma G, Ge C, Zhou L. Achieving reliable timestamp in the bitcoin platform[J/OL]. Peer-to-Peer Networking and App-lications, 2020(11)[2020-04-05]. https://doi.org/10.1007/s12083-020-00905-6.
[53] Fadhil M, Owenson G, Adda M. Locality based approach to improve propagation delay on the bitcoin peer-to-peer network[C]//Proceedings of the 2017 IFIP/IEEE Symposium on Inte-grated Network and Service Management, Lisbon, May 8-12, 2017. Piscataway: IEEE, 2017: 556-559.
[54] Henry R, Herzberg A, Kate A. Blockchain access privacy: challenges and directions[J]. IEEE Security & Privacy, 2018, 16(4): 38-45.
[55] Sarah M, Claudio O. Privacy-enhancing overlays in bitcoin[C]//Proceedings of the 2015 International Conference on Financial Cryptography and Data Security, Puerto Rico, Jan 30, 2015. Berlin: Springer, 2015: 127-141.
[56] Rivest R, Shamir A, Tauman Y. How to leak a secret[C]//Proceedings of the 2001 International Conference on the Theory and Application of Cryptology and Information Security, Gold Coast, Dec 9-13, 2001. Berlin, Heidelberg: Springer, 2001: 552-565.
[57] Ching Y L, Kai M C. On statistically-secure quantum homo-morphic encryption[J]. Quantum Information & Computa-tion, 2018, 18(9/10): 785-794.
[58] Zhu L H, Gao F, Shen M, et al. Survey on privacy preserving techniques for blockchain technology[J]. Journal of Com-puter Research and Development, 2017, 54(10): 2170-2186. 祝烈煌, 高峰, 沈蒙, 等. 区块链隐私保护研究综述[J]. 计算机研究与发展, 2017, 54(10): 2170-2186.
[59] Zhang A, Bai X Y. Survey of research and practices on block-chain privacy protection[J]. Journal of Software, 2020, 31(5): 1406-1434. 张奥, 白晓颖. 区块链隐私保护研究与实践综述[J]. 软件学报, 2020, 31(5): 1406-1434.
[60] Joseph P, Thaddeus D. The bitcoin lightning network: scalable off-chain instant payments[EB/OL]. (2016-01-14)[2020-06-20]. https://lightning.network/lightning-network-paper.pdf.
[61] Parizi R M, Homayoun S, Yazdinejad A, et al. Integrating privacy enhancing techniques into blockchains using side-chains[C]//Proceedings of the IEEE 32nd Canadian Confer-ence of Electrical and Computer Engineering, Edmonton, May 5-8, 2019. Piscataway: IEEE, 2019: 1-4.
[62] Atzei N, Bartoletti M, Cimoli T. A survey of attacks on ethereum smart contracts (SoK)[C]//Proceedings of the 2017 International Conference on Principles of Security and Trust, Uppsala, Apr 22-29, 2017. Berlin, Heidelberg: Springer, 2017: 164-186.
[63] Ouyang L W, Wang S, Yuan Y, et al. Smart contracts: archi-tecture and research progresses[J]. Acta Automatica Sinica, 2019, 45(3): 445-457. 欧阳丽炜, 王帅, 袁勇, 等. 智能合约：架构及进展[J]. 自动化学报, 2019, 45(3): 445-457.
[64] Karthikeyan B, Antoine D L, Cédric F, et al. Formal veri-fication of smart contracts: short paper[C]//Proceedings of the 2016 ACM Workshop on Programming Languages and Analysis for Security, Vienna, Oct 6-9, 2016. New York: ACM, 2016: 91-96.
[65] Eyal I, Gencer A E, Sirer E G, et al. Bitcoin-NG: a scalable blockchain protocol[C]//Proceedings of the 13th Usenix Con-ference on Networked Systems Design and Implementation, Santa Clara, Mar 16-18, 2016. Berkeley: USENIX Asso-ciation, 2016: 45-59.
[66] Dickerson T, Gazzillo P, Herlihy M, et al. Adding concu-rrency to smart contracts[C]//Proceedings of the 2017 ACM Symposium on Principles of Distributed Computing, Was-hington, Jul 23-26, 2017. New York: ACM, 2017: 303-312.