Ethereum Blockchain How does Ethereum work, anyway? (中文翻譯) Ethereum block architecture (Source file: BlockchainIllustrations) Smart Contract Ethereum Smart Contract Security Best Practices GitHub ConsenSys/smart-contract-best-practices RBAC-SC: Role-Based Access Control Using Smart Contract Decentralized Application Security Project Reentrancy Access Control Arithmetic Unchecked Low Level Calls Denial of Services Bad Randomness Front Running Time Manipulation Short Addresses Unknown Unknowns Solidity Learn X in Y minutes, where X=Solidity Truffle The most popular Ethereum development framework Truffle Boxes example applications and project templates 什麼是智能合約(Smart Contract)? 如何撰寫智能合約(Smart Contract)?(I) 如何撰寫智能合約(Smart Contract)?(II)建立加密代幣 如何撰寫智能合約(Smart Contract)?(III)建立標準代幣 OpenZeppelin a framework to build secure smart contracts on Ethereum Ethereum 智能合約開發筆記：編譯和部署合約的第一種姿勢 - 使用 Remix Ethereum區塊鏈！智能合約(Smart Contract)與分散式網頁應用(dApp)入門 區塊鏈技術-智能合約Solidity編程語言 亂數 由於區塊高度、timestamp 等不算是真正隨機亂數，可以加上 sender address 並 hash 過來增加亂度

COSCUP2018 這邊只能算是速記，這兩天晚上也沒時間整理成比較完整的筆記，未來應該也不會有機會整理了。 第一天幾乎都聽區塊鏈，第二天早上閒晃居多，下午跑去另一場活動，雖然還是有其他想聽的議程，但也就懶得跑來跑去了。 儘量不要用合約呼叫合約（Reentrance） ERC223、ERC677 ERC777 (ERC820) 增加 Operator 角色，讓第三方代管 token Transaction pool Local vs Remote Local: from this node, keep always Remote: from other nodes, might be dropped when pool full Pending vs Queue Pending: ready and included in the block Queued: transaction nonce is not in sequence Block gas limit: ~ 8,000,000 Empty block is valid eth-indexer: https://github.com/getamis/eth-indexer https://medium.com/getamis/%E5%A6%82%E4%BD%95%E5%BB%BA%E7%AB%8B-etherscan-%E6%9C%8D%E5%8B%99-c79c847ec4f 公有鍊問題（UPS 問題） 雷電網路 - Channel life cycles Open channel Join channel (deposit, init state) Off-chain transfers (update) Close channel (submit final state) Chanllenge period (for security)(timelock) Settle (withdrawal) Payment Channel Ethereum Plasma Map-Reduce Fraud proof: challenge misbehavior Different business logic could launch diff Plasma system litylang.org Lity 解 Overflow VM 層級 Compiler 層級 ERC223 auth modifier 漏洞 Gas 收費組成：Gas 基本費 21000，傳輸的資料，執行的運算 空合約 - 42901 ERC20 Token - 697051 刪除 -24000 資料儲存 新增: 20000 修改 5000 刪除 -15000 (仍算一次修改） 將非 0 值改 0 至少要一半費用 256 Bits 每四個寫入一次 每 byte 算 68 Gas 可更新的智能合約 佈署新合約，把舊的合約的帳戶資料放到新的合約，但資料不容易轉移 將邏輯和資料分開（Logic Conntract、Data Conntract） Data contract (getter/setter) owned by logic contract (upgradeable) Transfer owner of data contract 用 ENS 指向 logic contract，對外用 ENS，更新時只需要將名稱指向新合約 Proxy Delegate Call Logic Contract + Proxy Contract 更改 proxy contract 內儲存的合約地址變數 Zeppelin_os https://zeppelinos.org 更新的信任問題 NERVOS Information -> Blockchain Token Valuable + Verfied + Ownership Slide 區塊鏈上的二手票劵售票系統

Hyperledger Blockchain Technologies For Business Enterprise adoption patterns - Use case examples from practice - Into Hyperledger Fabric v1 (Hyperledger Meetup) IBM技术专家：Hyperleger Fabric 架构与部署实例解析 一文理解超級賬本Hyperledger Fabric的架構與坑 Consortium Blockchain Smart Contracts Hyperledger Architecture, Volume II, Smart Contracts Hyperledger Fabric Hyperledger Fabric GitHub Hyperledger Fabric Docs Components Membership Service Provider(MSP) Peer Order Channel Chaincode Participants Assets Transactions Endorser Committer Submitter Docker Images 1.1.0 $ curl -sSL https://goo.gl/6wtTN5 | bash -s 1.1.0 REPOSITORY TAG IMAGE ID CREATED SIZE hyperledger/fabric-ca x86_64-1.1.0 72617b4fa9b4 2 months ago 299MB hyperledger/fabric-tools x86_64-1.1.0 b7bfddf508bc 2 months ago 1.46GB hyperledger/fabric-orderer x86_64-1.1.0 ce0c810df36a 2 months ago 180MB hyperledger/fabric-peer x86_64-1.1.0 b023f9be0771 2 months ago 187MB hyperledger/fabric-javaenv x86_64-1.1.0 82098abb1a17 2 months ago 1.52GB hyperledger/fabric-ccenv x86_64-1.1.0 c8b4909d8d46 2 months ago 1.39GB hyperledger/fabric-zookeeper x86_64-0.4.6 92cbb952b6f8 3 months ago 1.39GB hyperledger/fabric-kafka x86_64-0.4.6 554c591b86a8 3 months ago 1.4GB hyperledger/fabric-couchdb x86_64-0.4.6 7e73c828fc5b 3 months ago 1.56GB 1.0.0