Overview of Covert Channel Research in Blockchain Environment

doi:10.3778/j.issn.1673-9418.2311102

Abstract

Abstract: Covert channel is a method to hide information in public communication channels for covert transmission, aiming at ensuring data transmission security and making third parties unaware of the covert communication process. However, with the continuous progress of traffic analysis technology, traditional network covert channels can no longer guarantee their security. Blockchain, as an emerging technology that combines cryptography, consensus algorithms, and P2P networks, has characteristics such as decentralization, traceability, anonymity, immutability, and security, making it an ideal platform for constructing covert channels. This paper first introduces blockchain technology, elaborates on the development process of covert channels, researches and summarizes the existing classification methods of covert channels. Then it summarizes the general model of blockchain covert channel on the basis of traditional network covert channel and divides the process of constructing covert channel into two main stages: information transmission and information extraction. Next, starting from the six-layer architecture of blockchain, the blockchain covert channels are analyzed in depth and the blockchain covert channels are divided into six categories according to different levels and subdivided based on the structure and mechanism of each layer, which can help better understand the construction process of blockchain covert channels and explore potential covert channels. Finally, this paper discusses the limitations of blockchain technology for covert channels and proposes future research directions.

Key words: blockchain, covert channel, covert channel classification, information transmission, information extraction

摘要： 隐蔽信道是将信息隐藏在公开的通信信道中进行隐蔽传输的方法，旨在保证数据传输的安全性，使第三方对隐蔽通信的过程毫无察觉。然而，随着流量分析技术的不断进步，传统的网络隐蔽信道已经无法保证其安全性。区块链作为一种新兴技术，结合了密码学、共识算法和P2P网络，具有去中心化、可追溯性、匿名性、不可变性和安全性等特性，成为了构建隐蔽信道的理想平台。首先，简要介绍了区块链技术，对隐蔽信道的发展历程进行了阐述，并对隐蔽信道现有的分类方式进行了研究和总结；然后，在传统网络隐蔽信道的基础上总结了区块链隐蔽信道的一般模型，将隐蔽信道的构建过程划分为信息传输和信息提取两个主要环节；接着，从区块链的六层架构出发，对区块链隐蔽信道进行了深入分析，按照不同的层次将区块链隐蔽信道分为了六大类，并依据每层的结构和机制进行细分，能够更好地理解区块链隐蔽信道的构建过程，挖掘潜在的隐蔽信道；最后，讨论了区块链技术给隐蔽信道带来的局限性，并提出了未来的研究方向。

关键词: 区块链, 隐蔽信道, 隐蔽信道分类, 信息传输, 信息提取

ZHANG Xuan, LI Leixiao, DU Jinze, SHI Jianping. Overview of Covert Channel Research in Blockchain Environment[J]. Journal of Frontiers of Computer Science and Technology, 2024, 18(6): 1438-1456.

张璇, 李雷孝, 杜金泽, 史建平. 区块链环境下隐蔽信道研究综述[J]. 计算机科学与探索, 2024, 18(6): 1438-1456.

References

[1] CHEN K. Roles and limitations of cryptographic techniques in information security[J]. Journal-China Institute of Communications, 2001, 22(8): 93-99.
[2] ROY R, CHANGDER S. Steganography with projection aided payload dimension reduction and reconstruction for military covert communication[J]. International Journal of Computer Applications, 2016, 139(3): 32-37.
[3] HANDEL T G, SANDFORD M T. Hiding data in the OSI network model[C]//Proceedings of the 2005 International Workshop on Information Hiding, Anderson, Jun 9, 2005. Berlin, Heidelberg: Springer, 1996: 23-38.
[4] NASR M, BAHRAMALI A, HOUMANSDR A. DeepCorr: strong flow correlation attacks on Tor using deep learning[C]//Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security, Toronto, Oct 15-19, 2018. New York: ACM, 2018: 1962-1976.
[5] WANG Y, WANG Y, WANG Z, et al. Research cooperations of blockchain: toward the view of complexity network[J]. Journal of Ambient Intelligence and Humanized Computing, 2022, 13(3): 1339-1352.
[6] 王翀, 王秀利, 吕荫润, 等. 隐蔽信道新型分类方法与威胁限制策略[J]. 软件学报, 2020, 31(1): 228-245.
WANG C, WANG X L, LV Y R, et al. Categorization of covert channels and its application in threat restriction techniques[J]. Journal of Software, 2020, 31(1): 228-245.
[7] 李彦峰, 丁丽萍, 吴敬征, 等. 网络隐蔽信道关键技术研究综述[J]. 软件学报, 2019, 30(8): 2470-2490.
LI Y F, DING L P, WU J Z, et al. Survey on key issues in networks covert channel[J]. Journal of Software, 2019, 30(8): 2470-2490.
[8] CHEN Z, ZHU L, JIANG P, et al. Blockchain meets covert communication: a survey[J]. IEEE Communications Surveys & Tutorials, 2022, 24(4): 2163-2192.
[9] 李雷孝, 杜金泽, 林浩, 等. 区块链网络隐蔽信道研究进展[J]. 通信学报, 2022, 43(9): 209-223.
LI L X, DU J Z, LIN H, et al. Research progress of blockchain network covert channel[J]. Journal on Communications, 2022, 43(9): 209-223.
[10] ALI M S, VECCHIO M, PINCHEIRA M, et al. Applications of blockchains in the Internet of things: a comprehensive survey[J]. IEEE Communications Surveys & Tutorials, 2018, 21(2): 1676-1717.
[11] KUMAR R, TRIPATHI R. Implementation of distributed file storage and access framework using IPFS and blockchain[C]//Proceedings of the 2019 5th International Conference on Image Information Processing, Shimla, Nov 15-17, 2019. Piscataway: IEEE, 2019: 246-251.
[12] HALPIN H, PIEKARSKA M. Introduction to security and privacy on the blockchain[C]//Proceedings of the 2017 IEEE European Symposium on Security and Privacy Workshops.Piscataway: IEEE, 2017: 1-3.
[13] YU K, TAN L, ALOQAILY M, et al. Blockchain-enhanced data sharing with traceable and direct revocation in IIoT[J]. IEEE Transactions on Industrial Informatics, 2021, 17(11): 7669-7678.
[14] 佘维, 霍丽娟, 刘炜, 等. 一种可隐藏敏感文档和发送者身份的区块链隐蔽通信模型[J]. 电子学报, 2022, 50(4): 1002.
SHE W, HU L J, LIU W, et al. A blockchain-based covert communication model for hiding sensitive documents and sender identity[J]. Acta Electonica Sinica, 2022, 50(4): 1002.
[15] XIE Y A, KANG J, NIYATO D, et al. Securing federated learning: a covert communication-based approach[J]. IEEE Network, 2023, 37(1): 118-124.
[16] ROSENTHAL R. Covert communication in the psychological experiment[J]. Psychological Bulletin, 1967, 67(5): 356.
[17] LAMPSON B W. A note on the confinement problem[J]. Communications of the ACM, 1973, 16(10): 613-615.
[18] SIMMONS G J. The prisoners?? problem and the subliminal channel[C]//Advances in Cryptology: Proceedings of Crypto 83. Boston: Springer US, 1984: 51-67.
[19] CRAVER S. On public-key steganography in the presence of an active warden[C]//Proceedings of the 1998 International Workshop on Information Hiding. Berlin, Heidelberg: Springer, 1998: 355-368.
[20] GIRLING C G. Covert channels in LAN??s[J]. IEEE Transactions on Software Engineering, 1987, 13(2): 292-296.
[21] WENDZEL S, ZANDER S, FECHNER B, et al. Pattern-based survey and categorization of network covert channel techniques[J]. ACM Computing Surveys, 2015, 47(3): 1-26.
[22] SWINNEN A, STRCKX R, PHILIPPAERTS P, et al. Proto-Leaks: a reliable and protocol-independent network covert channel[C]//Proceedings of the 8th International Conference on Information Systems Security, Guwahati, Dec 15-19, 2012. Berlin, Heidelberg: Springer, 2012: 119-133.
[23] DYATLOV A, CASTRO S. Exploitation of data streams authorized by a network access control system for arbitrary data transfers: tunneling and covert channels over the HTTP protocol[EB/OL]. (2003-06-15) [2023-11-24]. http://gray-world.net/projects/papers/covert_paper.txt.
[24] DANEAULT G, JOHNSON D. Client-initiated HTTP covert channels using relays[C]//Proceedings of the 2016 4th International Symposium on Digital Forensic and Security. Piscataway: IEEE, 2016: 32-37.
[25] GRANISZEWSKI W, KRUPSKI J, SZCZYPIORSKI K. SOMSteg-framework for covert channel, and its detection, within HTTP[J]. The Journal of Universal Computer Science, 2018, 24(7): 864-891.
[26] CAUICH E, GOMEZ C, WATANABE R. Data hiding in identification and offset IP fields[C]//Proceedings of the 2005 International Symposium and School on Advancex Distributed Systems. Berlin, Heidelberg: Springer, 2005: 118-125.
[27] ROWLAND C H. Covert channels in the TCP/IP protocol suite[J]. First Monday, 1997, 2(5): 1.
[28] PARTALA J. Provably secure covert communication on blockchain[J]. Cryptography, 2018, 2(3): 18-35.
[29] CAO H, YIN H, GAO F, et al. Chain-based covert data embedding schemes in blockchain[J]. IEEE Internet of Things Journal, 2020, 9(16): 14699-14707.
[30] WOLF M. Covert channels in LAN protocols[C]//Proceedings of the 1989 Workshop on Local Area Network Security. Berlin, Heidelberg: Springer, 1989: 89-101.
[31] TAHIR R, KHAN M T, GONG X, et al. Sneak-peek: high speed covert channels in data center networks[C]//Proceedings of the 35th Annual IEEE International Conference on Computer Communications. Piscataway: IEEE, 2016: 1-9.
[32] 李彦峰, 丁丽萍, 吴敬征, 等. 区块链环境下的新型网络隐蔽信道模型研究[J]. 通信学报, 2019, 40(5): 67-78.
LI Y F, DING L P, WU J Z, et al. Research on a new network covert channel model in blockchain environment[J]. Journal on Communications, 2019, 40(5): 67-78.
[33] ZHU L, LIU Q, CHEN Z, et al. A novel covert timing channel based on bitcoin messages[J]. IEEE Transactions on Computers, 2023, 72(10): 2913-2924.
[34] WU J, WU Y, YANG M, et al. POSTER: biTheft: stealing your secrets by bidirectional covert channel communication with zero-permission Android application[C]//Proceedings of the 22nd ACM SIGSAC Conference on Computer and Communications Security. New York: ACM, 2015: 1690-1692.
[35] 熊礼治, 朱蓉, 付章杰. 基于交易构造和转发机制的区块链网络隐蔽通信方法[J]. 通信学报, 2022, 43(8): 176-187.
XIONG L Z, ZHU R, FU Z J. Covert communication method of blockchain network based on transaction construction and forwarding mechanism[J]. Journal on Communications, 2022, 43(8): 176-187.
[36] CAI Z Y, ZHANG Y. Entropy based taxonomy of network convert channels[C]//Proceedings of the 2009 2nd International Conference on Power Electronics and Intelligent Transportation System. Piscataway: IEEE, 2009: 451-455.
[37] CABUK S. Network covert channels: design, analysis, detection, and elimination[D]. West Lafayette: Purdue University, 2006.
[38] ZANDER S, ARMITAGE G, BRANCH P. A survey of covert channels and countermeasures in computer network protocols[J]. IEEE Communications Surveys & Tutorials, 2007, 9(3): 44-57.
[39] 佘维, 荣欣鹏, 贾骏, 等. 区块链隐蔽通信的构建技术及检测方法研究综述[J]. 郑州大学学报(理学版), 2022, 54(6):1-11.
SHE W, RONG X P, JIA J, et al. Technology development and research status of blockchain covert communication and detection methods[J]. Journal of Zhengzhou University (Natural Science Edition), 2022, 54(6): 1-11.
[40] MAKHDOOM I, ABOLHASAN M, LIPMAN J. A comprehensive survey of covert communication techniques, limitations and future challenges[J]. Computers & Security, 2022, 120: 102784.
[41] DU B, HE D, LNO M, et al. The applications of blockchain in the covert communication[J]. Wireless Communications and Mobile Computing, 2022: 4618007.
[42] 宋上, 彭伟. BLOCCE+: 一种改进的基于区块链的隐蔽通信方法[J]. 重庆理工大学学报(自然科学), 2020, 34(9):238-244.
SONG S, PENG W. BLOCCE+: an improved blockchain-based covert communication approach[J]. Journal of Chongqing University of Technology (Natural Science), 2020, 34(9):238-244.
[43] LUO X, ZHANG P, ZHANG M, et al. A novel covert communication method based on bitcoin transaction[J]. IEEE Transactions on Industrial Informatics, 2021, 18(4): 2830-2839.
[44] WANG Z, ZHANG L, GUO R, et al. A covert channel over blockchain based on label tree without long waiting times[J]. Computer Networks, 2023, 232: 109843.
[45] TIAN J, GOU G P, LIU C, et al. DLchain: a covert channel over blockchain based on dynamic labels[C]//Proceedings of the 21st International Conference on Information and Communications Security, Beijing, Dec 15-17, 2019. Cham:Springer, 2020: 814-830.
[46] YIN J, CUI X, LIU C, et al. CoinBot: a covert botnet in the cryptocurrency network[C]//Proceedings of the 22nd International Conference on Information and Communications Security, Copenhagen, Aug 24-26, 2020. Cham: Springer, 2020: 107-125.
[47] BASUKI A I, ROSIYADI D. Joint transaction-image steganography for high capacity covert communication[C]//Proceedings of the 2019 International Conference on Computer, Control, Informatics and Its Applications. Piscataway: IEEE, 2019: 41-46.
[48] SHE W, HUO L, TIAN Z, et al. A double steganography model combining blockchain and interplanetary file system[J]. Peer-to-Peer Networking and Applications, 2021, 14(5): 3029-3042.
[49] ZHANG L, ZHANG Z, JIN Z, et al. An approach of covert communication based on the Ethereum Whisper protocol in blockchain[J]. International Journal of Intelligent Systems, 2021, 36(2): 962-996.
[50] BIRYUKOV A, FEHER D, VITTO G. Privacy aspects and subliminal channels in Zcash[C]//Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Security. New York: ACM, 2019: 1813-1830.
[51] ZHANG L, ZHANG Z, WANG W, et al. Research on a covert communication model realized by using smart contracts in blockchain environment[J]. IEEE Systems Journal, 2021, 16(2): 2822-2833.
[52] ZHANG L, ZHANG Z, WANG W, et al. A covert communication method using special bitcoin addresses generated by vanitygen[J]. Computers, Materials & Continua, 2020, 65(1): 597-616.
[53] GAO F, ZHU L, GAI K, et al. Achieving a covert channel over an open blockchain network[J]. IEEE Network, 2020, 34(2): 6-13.
[54] 司成祥, 高峰, 祝烈煌, 等. 一种支持动态标签的区块链数据隐蔽传输机制[J]. 西安电子科技大学学报, 2020, 47(5): 94-102.
SI C X, GAO F, ZHU L H, et al. Covert data transmission mechanism based on dynamic label in blockchain[J]. Journal of Xidian University, 2020, 47(5): 94-102.
[55] 蓝怡琴, 张方国, 田海博. 利用门罗币实现隐蔽通信[J]. 西安电子科技大学学报, 2020, 47(5): 19-27.
LAN Y Q, ZHANG F G, TIAN H B. Using Monero to realize covert communication[J]. Journal of Xidian University, 2020, 47(5): 19-27.
[56] ZHANG C, ZHU L, XU C, et al. EBDL: effective blockchain-based covert storage channel with dynamic labels[J]. Journal of Network and Computer Applications, 2023, 210: 103541.
[57] KURT A, ERDIN E, CEBE M, et al. LNBot: a covert hybrid botnet on bitcoin lightning network for fun and profit[C]// Proceedings of the 25th European Symposium on Research in Computer Security, Guildford, Sep 14-18, 2020. Cham:Springer, 2020: 734-755.
[58] SLEIMAN M D, LAUF A P, YAMPOLSKIY R. Bitcoin message: data insertion on a proof-of-work cryptocurrency system[C]//Proceedings of the 2015 International Conference on Cyberworlds. Piscataway: IEEE, 2015: 332-336.
[59] LIU L, LIU L, LI B, et al. MSCCS: a Monero-based security-enhanced covert communication system[J]. Computer Networks, 2022, 205: 108759.
[60] SWARD A, VECNA I, STONEDAHL F. Data insertion in bitcoin??s blockchain[J]. Ledger, 2018, 3.
[61] BARTOLETTI M, POMPIANU L. An analysis of bitcoin OP_RETURN metadata[C]//Proceedings of the 2017 International Workshops on Financial Cryptography and Data Security, Sliema, Apr 7, 2017. Cham: Springer, 2017: 218-230.
[62] 张涛, 伍前红, 唐宗勋. 基于比特币区块链的隐蔽信息传输研究[J]. 网络与信息安全学报, 2021, 7(1): 84-92.
ZHANG T, WU Q H, TANG Z X. Bitcoin blockchain based information convert transmission[J]. Chinese Journal of Network and Information Security, 2021, 7(1): 84-92.
[63] LIU S, FANG Z, GAO F, et al. Whispers on Ethereum: blockchain-based covert data embedding schemes[C]//Proceedings of the 2nd ACM International Symposium on Blockchain and Secure Critical Infrastructure. New York: ACM, 2020: 171-179.
[64] 刘九良. 基于区块链技术的信息隐藏方法研究[D]. 南京:南京信息工程大学, 2020.
LIU J L. Research on information hiding methods based on blockchain technology[D]. Nanjing: Nanjing University of Information Science & Technology, 2020.
[65] NIST C. The digital signature standard[J]. Communications of the ACM, 1992, 35(7): 36-40.
[66] SIMMONS G J. The subliminal channel and digital signatures[C]//Proceedings of the 1984 Workshop on the Theory and Application of Cryptographic Techniques. Berlin, Heidelberg: Springer, 1984: 364-378.
[67] GUO Z, SHI L, XU M, et al. MRCC: a practical covert channel over Monero with provable security[J]. IEEE Access, 2021, 9: 31816-31825.
[68] ALSALAMI N, ZHANG B. Uncontrolled randomness in blockchains: covert bulletin board for illicit activity[C]//Proceedings of the 2020 IEEE/ACM 28th International Symposium on Quality of Service. Piscataway: IEEE, 2020: 1-10.
[69] FRKAT D, ANNESSI R, ZSEBY T. ChainChannels: private botnet communication over public blockchains[C]//Proceedings of the 2018 IEEE International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData). Piscataway: IEEE, 2018: 1244-1252.
[70] FIONOV A. Exploring covert channels in bitcoin transactions[C]//Proceedings of the 2019 International Multi-Conference on Engineering, Computer and Information Sciences. Piscataway: IEEE, 2019: 59-64.
[71] ZHANG J, CHENG Y, DENG X, et al. A reputation-based mechanism for transaction processing in blockchain systems[J]. IEEE Transactions on Computers, 2021, 71(10): 2423-2434.
[72] 吕婧淑, 操晓春. 基于比特币系统的隐蔽通信技术[J]. 信息安全学报, 2021, 6(2): 143-152.
LV J S, CAO X C. Covert communication technology based on bitcoin[J]. Journal of Cyber Security, 2021, 6(2): 143-152.
[73] GLUHOVSKY V. EIP-627: Whisper specification[EB/OL]. (2017-05-14) [2023-11-24]. https://eips.ethereum.org/EIPS/eip-627/.
[74] BADEN M, TORRES C F, PONTIVEROS B B F, et al. Whispering botnet command and control instructions[C]//Proceedings of the 2019 Crypto Valley Conference on Blockchain Technology. Piscataway: IEEE, 2019: 77-81.
[75] RECABARREN R, CARBUNNAR B. TITHONUS: a bitcoin based censorship resilient system[J]. arXiv:1810.00279, 2018.
[76] 夏清, 窦文生, 郭凯文, 等. 区块链共识协议综述[J]. 软件学报, 2020, 32(2): 277-299.
XIA Q, DOU W S, GUO K W, et al. Survey on blockchain consensus protocol[J]. Journal of Software, 2020, 32(2): 277-299.
[77] 王群, 李馥娟, 倪雪莉, 等. 区块链共识算法及应用研究[J].计算机科学与探索, 2022, 16(6): 1214-1242.
WANG Q, LI F J, NI X L, et al. Survey on blockchain consensus algorithms and application[J]. Journal of Frontiers of Computer Science and Technology, 2022, 16(6): 1214-1242.
[78] 宋英齐, 冯荣权. 零知识证明在区块链中的应用综述[J]. 广州大学学报(自然科学版), 2022, 21(4): 21-36.
SONG Y Q, FENG R Q. A survey on applications of zero-knowledge proof in blockchain[J]. Journal of Guangzhou University (Natural Science Edition), 2022, 21(4): 21-36.
[79] 王群, 李馥娟, 王振力, 等. 区块链原理及关键技术[J]. 计算机科学与探索, 2020, 14(10): 1621-1643.
WANG Q, LI F J,WANG Z L, et al. Principle and core technology of blockchain[J]. Journal of Frontiers of Computer Science and Technology, 2020, 14(10): 1621-1643.
[80] 王珊. 面向博弈论的比特币区块链交易模式研究[D]. 兰州: 兰州交通大学, 2021.
WANG S. Research on bitcoin blockchain transaction pattern based on game theory[D]. Lanzhou: Lanzhou Jiaotong University, 2021.
[81] HE Y, LI H, CHENG X, et al. A blockchain based truthful incentive mechanism for distributed P2P applications[J]. IEEE Access, 2018, 6: 27324-27335.
[82] 李昕航, 李超, 张桂刚, 等. 区块链与数据库技术融合综述[J]. 计算机科学与探索, 2023, 17(4): 761-770.
LI X H, LI C, ZHANG G G, et al. Overview of blockchain and database fusion[J]. Journal of Frontiers of Computer Science and Technology, 2023, 17(4): 761-770.
[83] DU J Z, LI L X, XIONG X, et al. A blockchain covert communication method based on voting contract[C]//Proceedings of the 2023 IEEE 3rd International Conference on Power, Electronics and Computer Applications. Piscataway: IEEE, 2023: 1280-1282.
[84] AGUILAR M G, FUENTES J M D, MANZANO L G, et al. Zephyrus: an information hiding mechanism leveraging Ethereum data fields[J]. IEEE Access, 2021, 9: 118553-118570.
[85] 李德奇, 胡大裟, 刘云霞, 等. 基于区块链技术的僵尸网络命令控制信道研究[J]. 现代计算机, 2020(8): 30-36.
LI D Q, HU D S, LIU Y X, et al. Research on command control channel of Botnet based on blockchain technology[J]. Modern Computer, 2020(8): 30-36.
[86] 黄善云. 基于区块链的隐蔽通信技术研究[D]. 济南: 山东师范大学, 2023.
HUANG S Y. Research on covert communication technology based on blockchain[D]. Jinan: Shandong Normal University, 2023.