Ethereum for Ruby

RubyKaigi 2022
Mie Center for the Arts, Mie, Japan

Ethereum for Ruby
https://rubykaigi.org/2022/presentations/kurotaky.html#day3

Transcript

1. Ethereum for Ruby
   Yuta Kurotaki
   

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2. Yuta Kurotaki
   @kurotaky
   RubyKaigi Speaker 2018
   RailsGirls Coach 4,7~10,12,13th
   Yokohama.rb, K-Ruby
   Kagoshima RubyKaigi 01 Organizer
   Goods Sponsor (SUZURI, GMO Pepabo, Inc.)
   eth.rb Maintainer
   

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3. Contents
   • What is Ethereum?
   • Ethereum Keys and Addresses
   • Ethereum Signatures
   • Ethereum Transaction
   • Interact with Smart Contract
   

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4. What is Ethereum?
   

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5. Ethereum Blockchain
   • It is the Ethereum Blockchain invented by Vitalik in 2013
   • Trustless on the blockchain
   • It's called a world computer
   

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6. Ethereum Blockchain
   https://ethereum.org/en/whitepaper/
   APPLY(S,TX) -> S'
   

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7. Ethereum Blockchain
   https://ethereum.org/en/whitepaper/
   

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8. Etherscan
   https://etherscan.io/
   

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9. eth.rb
   • Let's take a look into the world of blockchain with eth.rb!
   • https://github.com/q9f/eth.rb
   

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10. Ethereum
    Keys and Addresses
    

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11. Blockchain Wallet
    • When users create a wallet such as
    MetaMask, an address of 0xabc.... is
    created.
    • This address is required on Ethereum
    https://metamask.io/
    

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12. Eth::Key
    • The library can create private/public key pairs
    • This can also show the required address on ethereum
    

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13. Address
    0x4cbeFF8966586874362ce4313D8f80cD404838a3
    

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14. Address
    • Calculate hash value of public key with Keccak256
    • Public key = K, last 20bytes of Keccak256(K)
    • Returns with 0x; 42 characters (40 without 0x)
    

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15. EIP-55
    • If the checksum is 8 or higher, the corresponding address letter is
    uppercase to prevent input errors.
    • EIP(Ethereum Improvement Proposals)
    

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16. EIP(Ethereum Improvement Proposals)
    https://eips.ethereum.org/EIPS/eip-55 https://eips.ethereum.org/EIPS/eip-721
    

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17. EIP-55
    • Addresses are not case sensitive
    • Can be veri
    fi
    ed if the checksum is used
    

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18. ENS
    • Ethereum Domain Name Service
    • kurotaky.eth
    https://ens.domains/
    https://eips.ethereum.org/EIPS/eip-137
    

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19. Ethereum Signatures
    

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20. Ethereum Signatures
    • ECDSA (Eliptic Curve Digital Signature Algorithm)
    • This is used for three purposes
    1. proof of authorization to make ETH payments or execute smart
    contracts
    2. proof that the signature is non-repudiation
    3. proof that no one has modi
    fi
    ed the transaction data since it was signed
    https://ethereum.org/en/developers/docs/transactions/
    

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21. personal_sign
    •
    

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22. sign
    

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23. sign
    

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24. Signature.verify
    

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25. EIP-155
    https://eips.ethereum.org/EIPS/eip-155
    

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26. Chain ID
    

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27. Transaction
    

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28. Transaction
    https://ethereum.org/en/whitepaper/
    

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29. Go Ethereum(geth)
    • Of
    fi
    cial Go implementation of the Ethereum protocol
    • geth --dev --http --ipcpath /tmp/geth.ipc
    https://geth.ethereum.org/
    

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30. geth
    

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31. Send ETH to another address
    • Geth (use http server)
    • use Eth::Client.create
    

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32. transfer_and_wait
    • 0.000000000000000001 = 1Wei
    • 0.000000000000000001 * 99000000000000000000 = 99ETH
    

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33. Eth::Unit
    

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34. Interact with Smart Contract
    

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35. Smart Contract
    • Can automatically execute contracts
    • Can execute programs on the blockchain
    

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36. Use Cases
    • DeFi (Decentralized Finance)
    • Identity (sign in with an ethereum account)
    • Cryptoeconomics
    • Stickers/badges
    • etc.
    

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37. Solidity
    https://docs.soliditylang.org/en/v0.8.16/introduction-to-smart-contracts.html#simple-smart-contract
    

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38. Solidity Compiler
    dummy.sol
    Solidity Compiler
    
    
    (solc)
    byte code
    
    
    6080604052.....
    EVM (Ethereum Virtual Machine)
    ABI
    
    
    (Application
    Binary
    Interface)
    EVM opcode
    
    
    PUSH1 0x80 PUSH1 0x40 MSTORE
    

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39. Eth::Contract.from_
    fi
    le
    • Conversion from sol
    fi
    les to Ruby objects
    

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40. dummy.sol
    

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41. ABI & bin
    

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42. Deployment of Smart Contracts
    • Deployment of Smart Contracts
    • call() and transact_and_wait()
    

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43. Sample App 1
    Sign-In with Ethereum
    https://github.com/q9f/ethereum-on-rails
    

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45. User
    • username
    • eth_address
    • eth_nonce
    

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46. Sample App 2
    Non-Fungible Token App
    https://gihyo.jp/magazine/wdpress/archive/2022/vol130
    https://github.com/kurotaky/sample-rails-dapp
    

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48. Let's try it!
    • This is a Rails application for creating Non Fungible Tokens
    • Please try it out !
    

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49. Conclusion
    

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50. Conclusion
    • Ethereum Blockchain Overview
    • How Ethereum Addresses Work and EIP
    • Overview of ethereum signatures
    • About executing smart contracts using eth.rb
    

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51. Future of eth.rb
    • Language diversity is important so that Ruby can also connect with the
    Ethereum world!
    • More examples of creating DApps with Ruby and Rails
    • Make it easy to connect to existing Rails applications
    

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52. Acknowledgements
    • @ethmarek
    • He brought me into the world of Ethereum.rb
    • @q9f
    • He promotes and maintains the eth.rb project with us
    • GMO Pepabo Web3 Development Team
    • RubyKaigi staff, organizers, committers and attendees
    

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53. Thank You!
    @kurotaky
    

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