狼人遊戲: 一種基於第二層網路與零知識證明之去中心化且具隱私性的區塊鏈應用

Abstract

由比特幣開始，區塊鏈的技術越來越受到重視。然而，區塊鏈效率與隱私的問題限制了其應用。基於區塊鏈的應用—狼人遊戲，便面臨隱私與效率的問題。在本篇論文中，我們提出了狼人遊戲的協議並實作，示範如何解決區塊鏈應用的速度與隱私問題，我們的作品闡述了我們所採用的方法和碰到的困難，希望可以在區塊鏈研究者和應用開發者碰到隱私與效率議題時有所幫助。 在隱私方面，狼人遊戲的玩家必須隱藏自己的腳色。在本篇論文中，我們的協議採用零知識證明的技術保護玩家的隱私。在效率議題方面，玩家在區塊鏈上浪費許多時間等待狼人遊戲裡的每一個動作，我們藉由區塊鏈的第二層解決方案，讓運算幾乎在鏈下進行，使遊戲在去中心化的情境下，流暢地進行，我們也和其他可能的解法比較時間上的效率，證明我們的協議擁有更好的表現。

Starting with Bitcoin, blockchain technology is gaining more and more attention. However, the problem of blockchain efficiency and privacy limits its application. The blockchain-based application - Werewolf game, also face privacy and efficiency issues. In this thesis, we propose the protocol of Werewolf game and implement Werewolf game to demonstrate how to solve speed and privacy issues of blockchain applications. Our work describes the methods we use and the difficulties we encounter that we hope blockchain researchers and application developers will find practically useful when facing privacy and efficiency issues. In terms of privacy, every player of Werewolf game must hide his role. In this thesis, our protocol protects privacy of players by zero-knowledge proof. In terms of efficiency issue, players spend a lot of time waiting every operation of Werewolf game on blockchain. We adopt the blockchain second layer solution to make almost all operations can be executed off chain. So game can go smoothly with no central authority. We also compare our time complexity with other schemes and prove our protocol has better performance.