近年來區塊鏈技術愈來愈成熟，不過都還是停留在虛擬貨幣身上，如果能把此技術用在其他方面就更好，由於偽造證書的情形越來越多，為了能簡單驗證又不會有偽造的情形，才以區塊鏈的技術去實作，區塊鏈的去中心化技術、私密性、不可否認性、不可竄改性，讓產生出來的證書具有說服力。
本次實驗使用以下方式去做，一種是以太坊另一種為IPFS，以太坊的部分先以智能合約的創建，讓不同身分能進去使用，像是使用者以及學校身分，然後不同身分有不同的權限，像是學校身分提供學生資料至平台上，讓需要讀取的人都能去執行，IPFS主要是先把學生的證書存放於IPFS平台上，在經過寫入區塊鏈中產生永久的鏈，任何人查看這條鏈就能讀取證書。
本篇研究希望能透過區塊鏈技術，解決目前產生證書所遭遇的困難，並為實現證書的保存與讀取提出一個可行方式。

In recent years, blockchain technology has becomeing  popular, however its major application is still limited to cryptocurrency. The technology has great potential for other area of applications. The increasing number of  faked official certificates has caught some attentions from the public. In the case of the blockchain technology,  the decentralization technology, privacy, non-repudiation, and non-destructive modification of the blockchain make the generated certificate convincing.
This experiment uses the following methods: the first is Ethereum and the second is IPFS. The smart contract component of Ethereum allows the creation of different level of roles and permissions such as regular users and school staffs. School staffs provide graduation status on smart contracts, allowing user to have a limited information. The IPFS method mainly stores the student's certificate on the IPFS and produce a permanent chain in the written blockchain. So anyone viewing this chain can read the certificate.
This study provides a convenient way to facility the verification of authorized certificates through the use of blockchain technology while the certificates are stored separately.

1 緒論 .................................................1
  1.1研究背景與動機 …………………………………………………… 1
  1.2研究目的………………………………………………………………2
  1.3研究流程與架構 ………………………………………………………3
2 文獻探討……………………………………………………………………4
  2.1區塊鏈 (Blockchain) …………………………………………………4
     2.1.1區塊鏈介紹	……………………………………………………4
     2.1.2區塊鏈結構	……………………………………………………6
  2.2以太坊 (Ethereum)………………………………………………………10
     2.2.1以太坊介紹	……………………………………………………10
     2.2.2以太坊的特點技術…………………………………………………10
  2.3星際檔案系統 (IPFS)……………………………………………………12
     2.3.1IPFS 介紹	……………………………………………………12
     2.3.2IPFS 運作方式……………………………………………………13
  2.4智能合約……………………………………………………………………15
     2.4.1智能合約介紹………………………………………………………15
3 架構……………………………………………………………………………19
  3.1架構流程與說明……………………………………………………………19
  3.2開發工具……………………………………………………………………21
4 系統實作………………………………………………………………………22
  4.1解決方案設計架構…………………………………………………………23
     4.1.1創建文憑文件…………………………………………………………24
  4.2以智能合約創建………………………………………………………………29
     4.2.1私鏈……………………………………………………………………29
     4.2.2智能合約與私鏈………………………………………………………30
     4.2.3以太坊錢包………………………………………………………………32
     4.2.4合約初始…………………………………………………………………34
  4.3假冒問題………………………………………………………………………38
5 結論…………………………………………………………………………………40
  5.1研究結論………………………………………………………………………40
  5.2研究貢獻………………………………………………………………………41
  5.3研究建議………………………………………………………………………42
參考文獻………………………………………………………………………………44
研討會論文……………………………………………………………………46
圖目錄
1.1研究架構…………………………………………………………………3
2.1區塊鏈流程……………………………………………………………6
2.2區塊鏈架構……………………………………………………………7
2.3分岔…………………………………………………………………………8
2.4運作過程狀態…………………………………………………………13
2.5讀取過程狀態……………………………………………………………13
3.1研究流程圖…………………………………………………………………19
3.2區塊鏈畢業證書發證系統…………………………………………20
3.3區塊鏈畢業證書發證系統 (畢業生端)……………………21
4.1流程介面……………………………………………………………………………22
4.2Hyperledger Rest server 介面………………………………23
4.3IPFS 傳輸方式………………………………………………………………24
4.4轉換流程……………………………………………………………………25
4.5轉換例子………………………………………………………………………26
4.6以太坊錢包……………………………………………………………………27
4.7以太坊錢包交易……………………………………………………………27
4.8交易狀態………………………………………………………………………28
4.9區塊鏈區別………………………………………………………………………29
4.10以太坊……………………………………………………………………………30
4.11Mist…………………………………………………………………………………30
4.12確認區塊數量…………………………………………………………………31
4.13撰寫合約……………………………………………………………………………31
4.14合約類別……………………………………………………………………………32
4.15MetaMask……………………………………………………………………………33
4.16MetaMask 錢包創建…………………………………………………………33
4.17Mist 畫面………………………………………………………………………………35
4.18節點流程………………………………………………………………………………38
4.19開啟IPFS………………………………………………………………………………39

表目錄
4.1geth 路徑…………………………………………………………………………34
4.2儲存個人資料……………………………………………………………………35
4.3合約初始……………………………………………………………………………36
4.4儲存個人資料………………………………………………………………………36
4.5function identify……………………………………………………36
4.6費用設定………………………………………………………………………………37
4.7註冊合約………………………………………………………………………………39

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