區(qū)塊鏈技術(shù)已成為解決多方協(xié)作信任問題的一種新方法。通過共識(shí)機(jī)制,用戶可以在不需要中央控制的情況下達(dá)成共識(shí)來完成某樣協(xié)作型任務(wù)。然而,將區(qū)塊鏈技術(shù)應(yīng)用于現(xiàn)實(shí)應(yīng)用面臨一定的困難,例如如何平衡在隱私安全性以及共識(shí)效率問題。共識(shí)機(jī)制是區(qū)塊鏈的技術(shù)基礎(chǔ),也是區(qū)塊鏈結(jié)構(gòu)中最重要的部分,通過節(jié)點(diǎn)分布式達(dá)成共識(shí)狀態(tài),實(shí)現(xiàn)去中心化的分布式記賬功能。當(dāng)前,用于物聯(lián)網(wǎng)區(qū)塊鏈系統(tǒng)的比較流行的共識(shí)協(xié)議是PoX系列共識(shí)協(xié)議,包括PoW,PoS等,但由于物聯(lián)網(wǎng)本身是一個(gè)開放系統(tǒng),各種設(shè)備允許接入到物聯(lián)網(wǎng)上,其中,一些惡意設(shè)備、不誠實(shí)設(shè)備的接入,以合法網(wǎng)絡(luò)身份發(fā)起一些針對(duì)物聯(lián)網(wǎng)系統(tǒng)的不良行為,例如雙花攻擊、欺騙攻擊等,能破壞物聯(lián)網(wǎng)的區(qū)塊鏈協(xié)議的正常運(yùn)行,有可能會(huì)導(dǎo)致整個(gè)物聯(lián)網(wǎng)網(wǎng)絡(luò)系統(tǒng)運(yùn)行效率低下、錯(cuò)誤決策等。本論文主要針對(duì)解決基于信譽(yù)的節(jié)點(diǎn)參與共識(shí)過程中經(jīng)常會(huì)遇到的技術(shù)難題:（1）如何有效合理的建立系統(tǒng)公平性問題,由于建立賬戶不需要成本,節(jié)點(diǎn)可以創(chuàng)建多個(gè)賬戶來參與共識(shí),每個(gè)賬戶維護(hù)著一個(gè)信譽(yù)度,這種做法可以提高出塊幾率且無需增加成本,嚴(yán)重影響了系統(tǒng)的公平性。（2）如何有效避免用戶為了逃避系統(tǒng)懲罰棄用舊賬戶改用新賬戶,... 

【文章來源】：哈爾濱工業(yè)大學(xué)黑龍江省 211工程院校 985工程院校

【文章頁數(shù)】：66 頁

【學(xué)位級(jí)別】：碩士

【文章目錄】：
摘要
ABSTRACT
Acknowledgement
NOMENCLATURE
Chapter 1 Introduction
    1.1 Research Background
        1.1.1 Technology breakthrough
    1.2 Blockchain Protocol
    1.3 Motivation
Chapter 2 Related Work
    2.1 Application Status of Blockchain in Io T
        2.1.1 Popular Consensus Protocols
    2.2 Analysis of Po X Protocols
        2.2.1 Proof of Activity Protocols
        2.2.2 Proof of Elapsed Time Protocols
    2.3 Current Po X Consensus in Io T
    2.4 Reputation Mechanism for Decentralized System
        2.4.1 Feedback Management Systems
        2.4.2 Reputation Mechanisms
    2.5 Chaining Mechanism
        2.5.1 Hash Functions
        2.5.2 Digital Signature
        2.5.3 Linking Blocks
        2.5.4 Order of appearance
Chapter 3 Reputation Incentive Scheme
    3.1 Proof of Reputation X
    3.2 Reputation Module
        3.2.1 Definitions
    3.3 Identity based Method
        3.3.1 Identity Registration with Smart Contract
        3.3.2 Steps to register an account
        3.3.3 Steps to logout an account
    3.4 Process
        3.4.1 Reputation Construction
        3.4.2 Blockchain Start-up
    3.5 Competition Cycle
    3.6 Incentive Mechanism
        3.6.1 Reward Functionality
        3.6.2 Penalty Funcitonality
    3.7 Rule of Updating Protocol Parameters
Chapter 4 Experiment and Evaluation
    4.1 Hypotheses and Configuration
    4.2 Ideal Reputation Growth
    4.3 Reputation Growth and Stability of the Algorithm
        4.3.1 Normal Reputation Growth
        4.3.2 Normal Reputation Growth with Reward Decay
        4.3.3 Stability
    4.4 Reputation Decay
    4.5 Computing Power Dependence Comparison
        4.5.1 Equally Powered Nodes Comparison
    4.6 Time Complexity Analysis
    4.7 Protocol Security Analysis
        4.7.1 Sybil Attack
        4.7.2 Fault Tolerance Attack
    4.8 Comparison with two other major protocols
Conclusions
References
Author’s Publications



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