Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
スマートコントラクトデザイン / Smart Contract Design
Search
Kenji Saito
PRO
October 27, 2024
Technology
0
68
スマートコントラクトデザイン / Smart Contract Design
慶應義塾大学大学院メディアデザイン研究科「サービスデザインプロジェクトB」2024秋 第4回にて使用したスライドです。
Kenji Saito
PRO
October 27, 2024
Tweet
Share
More Decks by Kenji Saito
See All by Kenji Saito
スマートコントラクトと分散ファイナンス / Smart Contracts and Decentralized Finance
ks91
PRO
0
57
シン・ブロックチェーン / Truth of Blockchain
ks91
PRO
0
86
パスワード/パスフレーズと認証 / Password, Passphrase and Authentication
ks91
PRO
0
32
git と GitHub / git and GitHub
ks91
PRO
0
35
ソフトウェアの開発と保守 / Software Development and Maintenance
ks91
PRO
0
47
インターネットの特徴 / Features of the Internet
ks91
PRO
0
34
インターネットのガバナンス / Governance of the Internet
ks91
PRO
0
29
暗号学的ハッシュ関数 / Cryptographic Hash Function
ks91
PRO
0
37
デジタル署名 / Digital Signature
ks91
PRO
0
32
Other Decks in Technology
See All in Technology
Node-RED × MCP 勉強会 vol.1
1ftseabass
PRO
0
170
Lambda Web Adapterについて自分なりに理解してみた
smt7174
5
130
Should Our Project Join the CNCF? (Japanese Recap)
whywaita
PRO
0
270
20250625 Snowflake Summit 2025活用事例 レポート / Nowcast Snowflake Summit 2025 Case Study Report
kkuv
1
340
PHPでWebブラウザのレンダリングエンジンを実装する
dip_tech
PRO
0
210
AIとともに進化するエンジニアリング / Engineering-Evolving-with-AI_final.pdf
lycorptech_jp
PRO
0
120
A2Aのクライアントを自作する
rynsuke
1
220
GeminiとNotebookLMによる金融実務の業務革新
abenben
0
240
より良いプロダクトの開発を目指して - 情報を中心としたプロダクト開発 #phpcon #phpcon2025
bengo4com
1
3.2k
Liquid Glass革新とSwiftUI/UIKit進化
fumiyasac0921
0
270
2年でここまで成長!AWSで育てたAI Slack botの軌跡
iwamot
PRO
4
810
SalesforceArchitectGroupOsaka#20_CNX'25_Report
atomica7sei
0
240
Featured
See All Featured
Scaling GitHub
holman
459
140k
Why You Should Never Use an ORM
jnunemaker
PRO
58
9.4k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
26
2.9k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
800
Into the Great Unknown - MozCon
thekraken
39
1.9k
How STYLIGHT went responsive
nonsquared
100
5.6k
Practical Orchestrator
shlominoach
188
11k
How to Ace a Technical Interview
jacobian
277
23k
Faster Mobile Websites
deanohume
307
31k
Designing for humans not robots
tammielis
253
25k
Building Adaptive Systems
keathley
43
2.6k
Transcript
Generated by Stable Diffusion XL v1.0 B 2024 4 (
) B 2024 — 4 — 2024-10-28 – p.1/58
https://speakerdeck.com/ks91/collections/service-design-project-b-2024-fall ( ) ( ) Discord Discord ( / /
) Zoom URL ( ) B 2024 — 4 — 2024-10-28 – p.2/58
( ) 1 10 7 • 2 10 14 •
3 10 21 • 4 11 28 • 5 11 4 1 6 11 11 2 7 11 18 8 11 25 ( ) ( ) 4 ( 3 ) ↓ B 2024 — 4 — 2024-10-28 – p.3/58
Ethereum ( ) (1) : ERC20 ( ) (2) :
(3) : Web3 B 2024 — 4 — 2024-10-28 – p.4/58
Ethereum ( ) B 2024 — 4 — 2024-10-28 –
p.5/58
Ethereum Vitalik Buterin, “Ethereum White Paper: A NEXT GENERATION SMART
CONTRACT & DECENTRALIZED APPLICATION PLATFORM” 12 (= ) = ⇒ → Dapps ( / / ) B 2024 — 4 — 2024-10-28 – p.6/58
( ) B 2024 — 4 — 2024-10-28 – p.7/58
. . . B 2024 — 4 — 2024-10-28 –
p.8/58
vs. Ethereum (Ether ) 13 13 B 2024 — 4
— 2024-10-28 – p.9/58
= run B 2024 — 4 — 2024-10-28 – p.10/58
Ether Ethereum EOA : Externally-Owned Account ( ) Ether EVM
EVM B 2024 — 4 — 2024-10-28 – p.11/58
EVM : Ethereum Virtual Machine ঢ়ଶ ֎෦ΞΫλʔ ΞΧϯτ &7. ίʔυ
&UIFSˠ(BT ىಈ ίϯτϥΫτ ϝοηʔδ͔ɺ৽͍ࣗ͠ಈΦϒδΣΫτ ΞΧϯτؒͰΓऔΓ͞ΕΔσʔλ&UIFS ετϨʔδ ঢ়ଶ` τϥϯβΫγϣϯ ηοτ σδλϧॺ໊ &7. ਓؒͱ͔ ࣗಈ ΦϒδΣΫτ Gas ( ( )) . . . B 2024 — 4 — 2024-10-28 – p.12/58
EVM : : ← : Solidity — JavaScript LLL —
Lisp Vyper — Python Fe — Vyper Rust ← NEW! Solidity Vyper Python B 2024 — 4 — 2024-10-28 – p.13/58
Solidity ( ) pragma solidityˆ0.7.0; contract IndivisibleAsset { /* */
string public _name; string public _symbol; uint256 public _quantity; address public _owner; constructor(string memory name, string memory symbol, uint256 quantity) public { _name = name; _symbol = symbol; _quantity = quantity; _owner = msg.sender; } function transfer(address to) public returns (bool) { require (_owner == msg.sender); _owner = to; return true; } } B 2024 — 4 — 2024-10-28 – p.14/58
( , ) (constructor) (deploy) = ( ) ( )
ETH Trusted Actor Model B 2024 — 4 — 2024-10-28 – p.15/58
Ethereum B 2024 — 4 — 2024-10-28 – p.16/58
(1) : ERC20 $ brownie bake token B 2024 —
4 — 2024-10-28 – p.17/58
pragma solidity ˆ0.6.0; /* 0.8.x */ contract Token { (
) : (EVM ) : constructor (...) public { /* */ : } function balanceOf(...) { /* ( ) */ : } : } constructor C (/* */ // ) B 2024 — 4 — 2024-10-28 – p.18/58
ERC-20 ERC (Ethereum Request for Comments) 20 https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md (EIP: Ethereum
Improvement Proposal) ← EIP ( ) contract ERC20 { function totalSupply() constant returns (uint totalSupply); function balanceOf(address _owner) constant returns (uint balance); function transfer(address _to, uint _value) returns (bool success); function transferFrom(address _from, address _to, uint _value) returns (bool success); function approve(address _spender, uint _value) returns (bool success); function allowance(address _owner, address _spender) constant returns (uint remaining); event Transfer(address indexed _from, address indexed _to, uint _value); event Approval(address indexed _owner, address indexed _spender, uint _value); } name/ , symbol/ , decimals/ approve allowance ERC-777 ( ) B 2024 — 4 — 2024-10-28 – p.19/58
ERC20 ERC20 ( ) ⇒ ERC20 ( ERC20 ) ERC20
⇒ B 2024 — 4 — 2024-10-28 – p.20/58
(fungible) ERC-20 → ERC-223 (draft) or ERC-777 ( )( )
(non-fungible) ERC-721 ( ) ERC-1155 ( ) ERC-3525 (SLOT ) B 2024 — 4 — 2024-10-28 – p.21/58
Token ( ) string public symbol; string public name; uint256
public decimals; uint256 public totalSupply; mapping(address => uint256) balances; . . . name, symbol decimals : 2 100 1.00 mapping balances B 2024 — 4 — 2024-10-28 – p.22/58
Token ( ) event Transfer(address from, address to, uint256 value);
Token function emit Transfer() ( ) B 2024 — 4 — 2024-10-28 – p.23/58
Token ( ) constructor( string memory _symbol, string memory _name,
uint256 _decimals, uint256 _totalSupply ) public { symbol = _symbol; name = _name; decimals = _decimals; totalSupply = _totalSupply; balances[msg.sender] = _totalSupply; } msg.sender _totalSupply B 2024 — 4 — 2024-10-28 – p.24/58
Token balanceOf() function balanceOf(address _owner) public view returns (uint256) {
return balances[_owner]; } B 2024 — 4 — 2024-10-28 – p.25/58
Token transfer() function transfer(address _to, uint256 _value) public returns (bool)
{ balances[msg.sender] = balances[msg.sender].sub(_value); balances[_to] = balances[_to].add(_value); emit Transfer(msg.sender, _to, _value); return true; } ( ↑ ) OpenZeppelin https://openzeppelin.org B 2024 — 4 — 2024-10-28 – p.26/58
(2) : B 2024 — 4 — 2024-10-28 – p.27/58
GitHub git clone $ git clone https://github.com/ks91/sample-smart-contracts.git sample-smart-contracts contracts, scripts
tests token Token Solidity 0.5 0.6/0.7 (Token ) Solidity B 2024 — 4 — 2024-10-28 – p.28/58
(m2 ) 1 1 B 2024 — 4 — 2024-10-28
– p.29/58
IndivisibleAsset string public _name_; string public _symbol_; uint256 public _quantity_;
address public _owner_; _name_ ( ) _symbol_ _quantity_ (m2 ) _owner_ ‘_’ Solidity . . . B 2024 — 4 — 2024-10-28 – p.30/58
IndivisibleAsset event Transfer(address indexed from, address indexed to); from to
indexed B 2024 — 4 — 2024-10-28 – p.31/58
IndivisibleAsset constructor (string name, string symbol, uint256 quantity) public {
_name_ = name; _symbol_ = symbol; _quantity_ = quantity; _owner_ = msg.sender; } B 2024 — 4 — 2024-10-28 – p.32/58
IndivisibleAsset getOwner() function getOwner() public view returns (address) { return
(_owner_); } B 2024 — 4 — 2024-10-28 – p.33/58
IndivisibleAsset transfer() function transfer(address to) public returns (bool) { require(_owner_
== msg.sender); _owner_ = to; emit Transfer(msg.sender, to); return true; } require (function ) ( ) $ brownie compile B 2024 — 4 — 2024-10-28 – p.34/58
scripts/indivisible asset.py from brownie import * def main(): accounts[0].deploy(IndivisibleAsset, "5322
Endo, Fujisawa", "mˆ2", 300) SFC (300m2 ) ( ) B 2024 — 4 — 2024-10-28 – p.35/58
from brownie import * import pytest def test_owner_and_transfer(IndivisibleAsset): asset =
accounts[0].deploy(IndivisibleAsset, "5322 Endo", "mˆ2", 300) assert asset.getOwner() == accounts[0] asset.transfer(accounts[1], {’from’: accounts[0]}) assert asset.getOwner() == accounts[1] try: asset.transfer(accounts[0], {’from’: accounts[0]}) done = 1 except: done = 0 assert done == 0 accounts[0] accounts[1] B 2024 — 4 — 2024-10-28 – p.36/58
$ pytest tests/test_indivisible_asset.py B 2024 — 4 — 2024-10-28 –
p.37/58
(3) : B 2024 — 4 — 2024-10-28 – p.38/58
transfer settle, retrieve asset, retrieve token 3 B 2024 —
4 — 2024-10-28 – p.39/58
1. ( ) 2. ( ) 3. ( ) B
2024 — 4 — 2024-10-28 – p.40/58
OneTimeEscrow settle() function settle() public returns (bool) { require(_token_.balanceOf(address(this)) >=
_price_); /* this */ require(_asset_.getOwner() == address(this)); _token_.transfer(_seller_ , _price_); _asset_.transfer(_buyer_); emit Settled(); /* */ return true; } settle() transfer ( / ) $ brownie compile B 2024 — 4 — 2024-10-28 – p.41/58
(1) from brownie import * import pytest def test_deploy_and_settle(Token, IndivisibleAsset,
OneTimeEscrow): asset = accounts[0].deploy(IndivisibleAsset, "5322 Endo", "mˆ2", 300) token = accounts[0].deploy(Token, "Test Token", "TEST", 18, "1000 ether") B 2024 — 4 — 2024-10-28 – p.42/58
(2) token.transfer(accounts[1], 300, {’from’: accounts[0]}) escrow = accounts[0].deploy(OneTimeEscrow, token, accounts[1],
asset, accounts[0], 300) accounts[0] accounts[1] 300 300 TX accounts[1] accounts[0] 300 bake Token 300 ETH wei B 2024 — 4 — 2024-10-28 – p.43/58
(3) token.transfer(escrow, 300, {’from’: accounts[1]}) asset.transfer(escrow, {’from’: accounts[0]}) assert token.balanceOf(accounts[0])
== 999999999999999999700 assert token.balanceOf(accounts[1]) == 0 assert token.balanceOf(escrow) == 300 assert asset.getOwner() == escrow accounts[1] ( ) 300 accounts[0] ( ) B 2024 — 4 — 2024-10-28 – p.44/58
(4) escrow.settle({’from’: accounts[0]}) assert token.balanceOf(accounts[0]) == 1000000000000000000000 assert token.balanceOf(accounts[1]) ==
0 assert token.balanceOf(escrow) == 0 assert asset.getOwner() == accounts[1] settle() accounts[0] OK B 2024 — 4 — 2024-10-28 – p.45/58
$ pytest tests/test_one_time_escrow.py : settle() ⇒ Discord B 2024 —
4 — 2024-10-28 – p.46/58
B 2024 — 4 — 2024-10-28 – p.47/58
1. (1) (2) Ethereum 2024 10 26 ( ) 23:59
JST B 2024 — 4 — 2024-10-28 – p.48/58
. . . . . . 3 2 ( )
( ) ( ) B 2024 — 4 — 2024-10-28 – p.49/58
N SFC ⇒ ( ) ( ) B 2024 —
4 — 2024-10-28 – p.50/58
L Ethereum ⇒ B 2024 — 4 — 2024-10-28 –
p.51/58
⇒ 20 Discord . . . B 2024 — 4
— 2024-10-28 – p.52/58
Web3 Web3 HTTPS B 2024 — 4 — 2024-10-28 –
p.53/58
B 2024 — 4 — 2024-10-28 – p.54/58
miro ( ) ( ) B 2024 — 4 —
2024-10-28 – p.55/58
B 2024 — 4 — 2024-10-28 – p.56/58
2. API (1) ( ) (2) Web API 2024 11
2 ( ) 23:59 JST B 2024 — 4 — 2024-10-28 – p.57/58
B 2024 — 4 — 2024-10-28 – p.58/58