臺灣博碩士論文加值系統

隨著 2008 年比特幣 (Bitcoin) 問世，區塊鏈技術逐年受到社會的重視，也啟發了許多區塊鏈技術的發展，例如台灣第一個區塊鏈技術 Gcoin 就是改良於比特幣，而以太坊 (Ethereum) 的出現成功的將智能合約融入到區塊鏈系統裡，又將區塊鏈技術帶入了下一個紀元。
智能合約是現今區塊鏈技術最重要的特色之一，它可以讓使用者不需要中間人，即可和其他使用者交易金錢、財產或任何有價值的東西。相比於傳統合約，他可以省去大量的人力、時間以及資源，卻可以帶來更穩定也更安全的效益。
在以太坊問世之後，區塊鏈上的智能合約技術蓬勃發展，然而主流的智能合約架構仍有一些可以改進的地方。因此本論文提出了一個新的智能合約架構，除了詳細介紹內容之外，也會探討其優點以及未來展望，並和當前最主流的兩個智能合約架構作比較。

With the advent of Bitcoin in 2008, blockchain technology has been paid much attention to society every year and has inspired the development of many other blockchain technology. For example, Gcoin blockchain is the first blockchain technology in Taiwan and it is derived from Bitcoin Core. And the success of merging smart contract into Ethereum blockchain brings the development of blockchain technology into the next era.
Smart contract is one of the most important features in blockchain technology nowadays, which allows users to trade money, property of anything valuable without a middleman. Compared to traditional contracts, it can save a lot of manpower, time, and resources, but can bring more stable and more secure results.
After the advent of Ethereum, the development of blockchain-based smart contract flourished. However, there are still some parts where the mainstream smart contract architecture can be approved. Therefore, this thesis proposes a new model, in addition to the details of the design, will also explore its advantages and future works, and the comparison to two current mainstream smart contract architectures.

Contents
誌謝 i
摘要 ii
Abstract iii
Contents iv
List of Figures vi
List of Tables vii
Chapter 1 Introduction 1
Chapter 2 Background 3
2.1 Transaction and UTXO 3
2.2 Multi-signature 4
2.3 OP_RETURN 4
2.4 Gcoin Blockchain 5
2.5 Smart Contract 5
Chapter 3 Related Work 7
3.1 Ethereum 7
3.2 HyperLedger fabric 8
3.3 Motivation 9
Chapter 4 Architecture Design 11
4.1 Overview 11
4.2 System Architecture 11
4.2.1 Nodes 11
4.2.2 Virtual Machine 13
4.2.3 State 13
4.2.4 Transactions 14
4.3 Transaction Flow 17
4.3.1 Assumption 17
4.3.2 Deploy Contract 17
4.3.3 Invoke Contract 19
4.3.4 Reconstruct the state 21
Chapter 5 Analysis 23
5.1 Flexibility 23
5.2 Scalability 24
5.3 Efficiency 26
Chapter 6 Future work 28
6.1 State file pruning 28
6.2 Message queue 29
6.3 Transfer Contract 30
Chapter 7 Conclusion 31
Bibliography 32

[1] Bitcoin: A peer-to-peer electronic cash system. Nakamoto, S. (2008).
[2] Ethereum Foundation. Ethereum’s white paper. https://github.com/ethereum/wiki/wiki/White-Paper (2014).
[3] Ethereum: A Secure Decentralised Generalised Transaction Ledger. DR. Gavin Wood (2016).
[4] Gcoin White Paper.
https://github.com/OpenNetworking/gcoin-community/wiki/Gcoin-white-paper-English (Retrieved July, 2017)
[5] IBM HyperLedger Fabric Document.
https://hyperledger-fabric.readthedocs.io/en/latest/index.html (Retrieved July, 2017)
[6] Mastering Bitcoin. Andreas M. Antonopoulos. O''Reilly Media. (2014)