簡易檢索 / 詳目顯示
| 研究生： |
詹琨泰 Chan, Kun-Tai |
|---|---|
| 論文名稱： |
分散式環境中基於聲譽的信任度評估機制及其在智能合約之應用 Reputation-based Trust Evaluation Mechanism for Decentralized Environments and It’s Application Based on Smart Contracts |
| 指導教授： |
左瑞麟
Tso, Raylin |
| 口試委員: |
左瑞麟
Tso, Raylin 陳恭 Chen, Kung 許建隆 Hsu, Chien-Lung 李榮三 Lee, Jung-San 黃仁俊 Huang, Ren-Junn |
| 學位類別： |
碩士
Master |
| 系所名稱： |
理學院 - 資訊科學系 |
| 論文出版年： | 2017 |
| 畢業學年度： | 105 |
| 語文別： | 英文 |
| 論文頁數： | 64 |
| 中文關鍵詞： | 區塊鏈 、去中心化 、PGP 、智能合約 、小世界理論 、信任度 |
| 外文關鍵詞： | Blockchain, Decentralized, PGP, Smart contract, The Small World Problem, Trust degree |
| 相關次數： | 點閱：224 下載：18 |
| 分享至: |
| 查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報 |
近年來區塊鏈技術及其相關應用成為熱門焦點，區塊鏈最大的特色包含去中心化以及匿名性等特性，然而在這樣的分散式網路中我們很難判斷對方是否值得信賴，在數位憑證中我們透過可信賴第三方擔任憑證中心為用戶簽發金鑰憑證以此建立用戶之間的信賴關係，但在區塊鏈此種分散式網路中找到一個可信賴第三方實屬不易，並且可能會與區塊鏈去中心化之特性背道而馳，因此本研究參考PGP信任網與小世界理論的概念，建立一套可適用於分散式環境中基於聲譽的信任度評估機制，並將此機制結合智能合約實現一個信任度評估機制購物平台，目的希望用戶與陌生人交易前，可透過此機制計算出信任度，提供用戶做為參考，幫助用戶更容易判斷陌生人是否可信，以降低受騙風險。
In recent years, the blockchain technology and its relevant applications become hot spots. The greatest feature of the blockchain is the decentralization. Nonetheless, it is difficult for us to judge whether the other person get involved in the decentralized network is credible. Furthermore, it is difficult to find a reliable third party in such a point-to-point network. Consequently, this paper refers to the PGP web of trust and the small world problem to establish a set of reputation-based trust evaluation mechanism for decentralized environments, we combine this mechanism with a smart contract to achieve a trust evaluation mechanism shopping platform, It is expected that achievements of the paper can facilitate people’s judgment regarding the reliability of strangers and reduce the risks of being deceived.
Chapter 1 Introduction 1
1.1 Research Motivation 1
1.2 Research Purpose 2
1.3 Research Contribution 2
1.4 Organization 3
Chapter 2 Background and Related Works 5
2.1 Digital Signatures 5
2.1.1 The Generation and Verification of Digital Signatures 5
2.2 Digital Certificate 7
2.2.1 Certificate Authority 7
2.2.2 Scenario of Issuing a Digital Certificate 8
2.3 Pretty Good Privacy (PGP) 10
2.3.1 Key Ring 11
2.3.1.1 Public Key Ring 11
2.3.1.2 Private Key Ring 13
2.3.2 PGP Web of Trust 13
2.3.2.1 Confirm the Public Key through User's Own Digital Signature 14
2.3.2.2 Confirm the Public Key through the Person that User Fully Trust 14
2.3.2.3 Confirm the Public Key through the Person that User Marginally Trust 15
2.4 Elliptic Curve Cryptography 16
2.5 Blockchain 17
2.6 Smart Contract 18
2.7 The Small World Problem 20
2.8 Dijkstra Algorithm 21
2.9 Literatures Regarding the Calculation of Trust Degree 24
Chapter 3 Reputation-based Trust Evaluation Mechanism 28
3.1 Records of Trust Degree 28
3.2 Scenarios of Trust Evaluation 30
3.2.1 Scenario 1: Direct Relationship 31
3.2.2 Scenario 2: Indirect Relationship 34
3.2.3 Scenario 3: No Indirect Relationship 40
3.2.4 Scenario 4: New Seller 40
Chapter 4 System Implementation 41
4.1 Implementation and Simulation Testing of Trust Evaluation Mechanism 41
4.1.1 Implementation Environment 41
4.1.2 Simulation Testing 41
4.2 The Shopping Platform Composed of Smart Contract and Trust Evaluation Mechanism 46
4.2.1 Implementation Environment 46
4.2.2 System Architecture and Smart Contract 46
4.2.3 Operation Interface and Process Flow 51
4.3 Result and Discussion of Experiment 57
Chapter 5 Comparison of Trust Evaluation Mechanisms 59
5.1 The Characteristics of Our Mechanism 59
5.2 Comparison Results 60
Chapter 6 Conclusion 62
References 63
[1] Garfinkel, S. (1995). PGP: pretty good privacy. " O'Reilly Media, Inc."
[2] Zyskind, G., & Nathan, O. (2015, May). Decentralizing privacy: Using blockchain to protect personal data. In Security and Privacy Workshops (SPW), 2015 IEEE (pp. 180-184). IEEE.
[3] Zhang, F., Cecchetti, E., Croman, K., Juels, A., & Shi, E. (2016, October). Town crier: An authenticated data feed for smart contracts. In Proceedings of the 2016 ACM SIGSAC Conference on Computer and Communications Security(pp. 270-282). ACM.
[4] Travers, J., & Milgram, S. (1967). The small world problem. Phychology Today, 1, 61-67.
[5] Nakamoto, S. (2008). Bitcoin: A peer-to-peer electronic cash system.
[6] Andrychowicz, M., Dziembowski, S., Malinowski, D., &Mazurek, L. (2014, May). Secure multiparty computations on bitcoin. In Security and Privacy (SP), 2014 IEEE Symposium on (pp. 443-458). IEEE.
[7] Li,Y. M., Chen, J. C.,&Li, T. Y.(2007, May). A Blog System with Trust Mechanism.18th International Conference on Information Management.
[8] Meng, X. F., Zhang, L., & Wang, X. (2009). Research on trust model of P2P electronic commerce [J]. Application Research of Computers, 8, 077.
[9] Qiao, X. Q., Yang, C., Li, X. F., & Chen, J. L. (2011). A trust calculating algorithm based on social networking service users' context. JisuanjiXuebao(Chinese Journal of Computers), 34(12), 2403-2413.
[10] Gao,Y.,&Yuan, Y. (2014). The Research on Global Trust Algorithm Based on Social Network.from: http://www.paper.edu.cn.
[11] 許鑫, &翟曉娟. (2008). 信任度計算與信任傳遞協議設計的研究. 現代圖書情報技術, 24(3),(pp. 32-39).
[12] Recommendation-for-Key-Management-Part1: General , from:http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-57pt1r4.pdf
[13] 智能合約-MBA智庫百科, from:http://wiki.mbalib.com/zh-tw/%E6%99%BA%E8%83%BD%E5%90%88%E7%BA%A6
[14] Facebook research, from: https://research.fb.com/three-and-a-half-degrees-of-separation/?hc_location=ufi
[15]Heineman, G. T., Pollice, G., &Selkow, S. Algorithms in a Nutshell, Oreilly Media. ISBN 978-0-596-51624-6.
[16] Stallings, W., &Tahiliani, M. P. (2014). Cryptography and network security: principles and practice (Vol. 6). London: Pearson.
[17]結城浩.(2011). 密碼學與網路安全應用.旗標出版股份有限公司.
[18]林展民.(2016). 以智能合約實現快速醫療保險理賠.國立政治大學資訊科學系碩士論文.
