What is a blockchain? 區塊鍊是什麼?

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专想阮
5 years ago
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1 Overview of Blockchain Protocols 區塊鏈協議的概述

2 What is a blockchain? 區塊鍊是什麼?

3 A blockchain is... 區塊鍊是... Decentralized computer network 去中心化的計算機網絡 Keeps track of and processes transactions sent by users 追踪和處理用戶發送的交易 Consensus algorithm ensures that the network agrees on the order of the transactions and the result 共識算法保證整個網絡同意交易的順序和結果 Once the consensus algorithm confirms a transaction, it cannot be reverted 共識算法敲定一個交易以後, 不可能撤銷它

4 Benefits 好處 Single database with rapid consensus - allows for extremely fast clearing and settlement (eg seconds, instead of 1-3 days) 統一的數據庫和快速的共識算法允許快速的清算和結算 (3-60 秒代替 1-3 天 ) Massively fault-tolerant (even if many nodes go offline or are hacked, the system continues to work) 非常容錯 : 即使很多節點離線或者被黑, 系統繼續運行 Not dependent on any single administrator or organization 不依靠與一個管理人員或公司

5 What kinds of blockchains are there? 有什麼樣的區塊鏈?

6 Types of blockchain 區塊鏈的類型

7 Applications 應用

8 Bitcoin 比特幣 First blockchain, created in 2009 第一個區塊鏈, 2009 年發布 One application: decentralized peer-to-peer digital currency 一個應用 : 去中心化點對點的數字貨幣 Uses proof of work consensus (mining) 使用工作量證明 ( 挖礦 ) 的共識算法 Public blockchain (anyone can participate by mining, sending transactions, etc) 公有鏈 : 每個人可以參加 ( 挖, 發送交易, 等等 )

9 Namecoin, colored coins, etc 域名幣, 有色幣, 等等 Namecoin: Bitcoin-like blockchain, but serves as a decentralized domain name registration system 域名幣 : 類似於比特幣的區塊鏈, 但是充當去中心化域名註冊的系統 Users need to install a special plugin to view.bit websites registered on the blockchain in their browsers 用戶需要安裝特殊的插件為了在瀏覽器看.bit 區塊鏈上註冊的網站 Colored coins: digital asset registry protocol on the bitcoin blockchain 有色幣 : 比特幣區塊鏈上的數字資產註冊協議

10 Swiss army knife protocols 瑞士軍刀的協議 Support multiple applications, but have a special transaction type for each application 支持多種應用, 但是每個應用有特定交易的類型 Utility broader, but still limited 用途更寬闊, 但是還有限

application on Ethereum by writing it as smart contract code and uploading it

11 Ethereum 以太坊 General-purpose blockchain protocol containing a Turing-complete programming language 通用區塊鏈協議, 包含一個圖靈完全的編程語言 Developers can create any application on Ethereum by writing it as smart contract code and uploading it to the blockchain 開發者可以以太坊上實現任何應用, 只需要寫智能合約的代碼和上載代碼到區塊鏈 Independent blockchain 獨立的區塊鏈

12 Ethereum 以太坊 Very little is in the box : almost all functionality (including digital tokens, multisignature accounts, privacy preserving features) needs to be implemented on top of the platform as code 在協議內功能很少 : 幾乎一切 ( 包括數字資產, 多簽名的賬戶, 保護隱私的功能 ) 需要寫以太坊上的代碼實現 This allows for extreme flexibility in all areas (application logic, account security, digital asset standardization, etc) 這個原則允許極端伸縮性在每個領域 ( 應用的邏輯, 賬戶的安全性, 數字資產的標準化, 等等 )

13 Examples 例子 Digital token Domain name registration 數字代幣域名註冊系統 data balances[] def send(to, value): if self.balances[msg.sender] >= value: self.balances[msg.sender] -= value self.balances[to] += value data domains[](owner, ip) def register(addr): if not self.domains[addr].owner: self.domains[addr].owner = msg.sender def set_ip(addr, ip): if self.domains[addr].owner == msg.sender: self.domains[addr].ip = ip

14 Smart contracts 智能合約 Computer code that directly controls digital assets or business logic 代碼直接控制數字資產或業務邏輯 Concept first conceived by Nick Szabo in 1997 概念 1997 年 Nick Szabo 發明的 Vending machine as a smart contract implemented in hardware 自動收貨機為硬件實現的智能合約 If event X happens, automatically send Y coins to address A 如果 X 發生, 自動發 Y 個幣給地址 A

15 Applications 應用 Complex asset types (eg. UBS smart bond project, electricity trading) 複雜資產的類型 ( 例子 : UBS 的智能債權的項目, 能源交換 ) Multisignature escrow 多簽名的提存 Financial contracts 金融合約 Options, derivatives, etc 期權, 衍生品, 等等

16 Consensus algorithms 共識算法

17 Public chain consensus 公有鏈的共識 Anyone can participate 每個人可以參加 To solve the sybil attack problem, the protocol measures how much economic resources each participant is contributing 以便解決 sybil 攻擊的問題, 協議測量每個參與者貢獻多少資源 PoW: 1 unit of computing power = 1 vote 工作量證明 : 一個計算能力的單位 = 1 票 PoS: 1 coin = 1 vote 股權證明 : 1 個數字幣 =1 票

18 Consortium chain consensus 联盟链的共识 Traditional byzantine fault tolerant consensus 傳統拜占庭容錯的共識算法 Existed since 1980s, very thoroughly researched 自從 1980 年代存在, 已經很深入學術研究的 Rapid finality 交易快速敲定 Efficiency limits beyond ~30 nodes 30 個節點以上有效率的限制 Complex to implement 算法複雜, 實現有點難

19 Consortium chain consensus 联盟链的共识 Round-robin consensus (eg. DPOS) 循環的共識 ( 包括 DPOS ) Simple to implement 實現很容易 Can support very large numbers of nodes 支持很大節點的數量 Slower to confirm transactions 敲定交易更慢

20 Solutions to technical challenges (future) 技術問題的解決方案 ( 未來 )

21 Scalability 可擴展性 Current public blockchain protocols can process ~3-20 tps, consortium chain protocols up to 現有的公有鏈協議處理 3-20 個交易每秒, 聯盟鏈的協議個 On-chain scaling 鏈上的擴展 Require each node to have a large amount of computing power (more feasible in consortium chains) 要求每個節點有大量的計算能力 ( 在聯盟鏈更可行 ) Sharding 拆分 Layer 2 solutions (eg. channels / lightning network) 第二層的解決方案 ( 比如 : 渠道 / 閃電網絡 )

22 Privacy 隱私 Data on a blockchain is visible to all participants; this may not be acceptable for some applications 每個參與者可以看區塊鏈上的數據, 對一些應用不可行 But we can combine blockchain tech with traditional cryptography (hashing, encryption, zero-knowledge proofs) and often get the blockchain's security and traditional cryptography's privacy at once 但是我們可以結合區塊鏈技術和傳統密碼學技術 ( 哈希, 加密, 零知識證明 ) 和經常同時得到區塊鏈的安全性和傳統密碼學的隱私 eg. Zerocash (privacy-preserving digital currency based on blockchain+zkp tech) 比如, Zerocash ( 保護隱私的數字貨幣基於區塊鍊和零知識證明技術 )

第一章 1.0 Bitcoin Bitcoin Bitcoin 1-1 decentralized miner spreadsheet

第一章 1.0 Bitcoin Bitcoin Bitcoin 1-1 decentralized miner spreadsheet 2 Bitcoin BTC Btc Litecoin Dogecoin Ripple NXT Peercoin http://coinmarketcap.com/ 1-1 加密貨幣比特幣協定與用戶比特幣區塊鏈 BTC Litecoin Dogecoin Counterparty