続・スマートコントラクトと分散ファイナンス / Smart Contracts and Decentralized Finance, Continued

早稲田大学大学院経営管理研究科「フィンテック ─ 金融革新とインターネット」2025 夏の第7-8回で使用したスライドです。

Transcript

1. Light and Shadow — Generated by Stable Diffusion 3.5 — 2025 9-10 (WBS) — 2025 9-10 — 2025-07-07 – p.1/58
2. https://speakerdeck.com/ks91/collections/fintech-2025-summer — 2025 9-10 — 2025-07-07 – p.2/58
3. ( ) 1 6 9 (1) • 2 6 9 (2) • 3 6 16 Web3 (1) • 4 6 16 Web3 (2) • 5 6 23 (1) • 6 6 23 (2) • 7 6 30 (1) • 8 6 30 (2) • 9 7 7 (1) • 10 7 7 (2) • 11 7 14 12 7 14 13 7 21 (1) ( ) 14 7 21 (2) ( ) W-IOI ( ) — 2025 9-10 — 2025-07-07 – p.3/58
4. ( 20 ) 1 ↑ 2 ↓ 2025 3 4 (TCP/IP ) 5 6 7 8 ↑ 9 ↓ 2024 ( ) 10 World Wide Web 11 Web API 12 * 13 git GitHub 14 (6/23 ) / (2 ) OK / — 2025 9-10 — 2025-07-07 – p.4/58
5. ( ) Ethereum — 2025 9-10 — 2025-07-07 – p.5/58
6. ( ) Ethereum ( ) — 2025 9-10 — 2025-07-07 – p.6/58
7. ( ) — 2025 9-10 — 2025-07-07 – p.7/58
8. Y The DAO ⇒ Monacoin (2018), Bitcoin Gold (2020), etc. Ethereum The DAO ( ) ( ) Ethereum Classic — 2025 9-10 — 2025-07-07 – p.8/58
9. M AI AI? ( ) AI ⇒ AI — 2025 9-10 — 2025-07-07 – p.9/58
10. H Ethereum NFT ⇒ NFT — 2025 9-10 — 2025-07-07 – p.10/58
11. H ( ) ⇒ — 2025 9-10 — 2025-07-07 – p.11/58
12. S ( JPMC CBDC( )) 1 1USD Bit Coin ⇒ OK CBDC — 2025 9-10 — 2025-07-07 – p.12/58
13. S proof of state proof of works proof of stake ⇒ PoS PoS 2 — 2025 9-10 — 2025-07-07 – p.13/58
14. N ⇒ — . . . Discuss. — 2025 9-10 — 2025-07-07 – p.14/58
15. Ethereum Ethereum ( ) — 2025 9-10 — 2025-07-07 – p.15/58
16. — 2025 9-10 — 2025-07-07 – p.16/58
17. Ethereum · → · → · → — 2025 9-10 — 2025-07-07 – p.17/58
18. ↑ — 2025 9-10 — 2025-07-07 – p.18/58
19. (by ) 1. 2. ( ) ( ) . . . cf. by McLuhan cf. by McLuhan → — 2025 9-10 — 2025-07-07 – p.19/58
20. by ⇒ ⇒ — 2025 9-10 — 2025-07-07 – p.20/58
21. by SNS AI AI ⇒ ( ) ⇒ — 2025 9-10 — 2025-07-07 – p.21/58
22. Ethereum EVM (Ethereum Virtual Machine) — 2025 9-10 — 2025-07-07 – p.22/58
23. Ethereum Vitalik Buterin, “Ethereum White Paper: A NEXT GENERATION SMART CONTRACT & DECENTRALIZED APPLICATION PLATFORM” (Dec. 2013∼) 12 ( ) (= ) = = ( ) CPU ⇒ DApps DApps = / — 2025 9-10 — 2025-07-07 – p.23/58
24. = ( ) run = → — 2025 9-10 — 2025-07-07 – p.24/58
25. [Lamport 1984][Schneider 1990] ( ) (1) 0 ( ) (2) (3) (4) ( ) ← — 2025 9-10 — 2025-07-07 – p.25/58
26. Ether (ETH) Ethereum EOA : Externally-Owned Account ( ) ( ) ( ) ( ) ← Ether ( ) EVM EVM = Ethereum = — 2025 9-10 — 2025-07-07 – p.26/58
27. EVM : Ethereum Virtual Machine ঢ়ଶ ֎෦ΞΫλʔ ΞΧ΢ϯτ &7. ίʔυ &UIFS
    ˠ
    (BT ىಈ ίϯτϥΫτ ϝοηʔδ
    ͔ɺ৽͍ࣗ͠ಈΦϒδΣΫτ ΞΧ΢ϯτؒͰ΍ΓऔΓ͞ΕΔσʔλ΍
    &UIFS ετϨʔδ ঢ়ଶ` τϥϯβΫγϣϯ ηοτ σδλϧॺ໊ &7. ਓؒͱ͔ ࣗಈ ΦϒδΣΫτ ( ) Gas ( EVM = ( burn)) — 2025 9-10 — 2025-07-07 – p.27/58
28. / / (1) Ethereum Bitcoin ( OK) 1 — 2025 9-10 — 2025-07-07 – p.28/58
29. / / (2) 3 ( ) · ( ) ( ) 1 — 2025 9-10 — 2025-07-07 – p.29/58
30. / / (3) ( ) ( ) 1 ( ) 1,500 3,000 (← . . . ) Ethereum 2022 9 — 2025 9-10 — 2025-07-07 – p.30/58
31. / / (4) Gwei Gwei ETH 32 ETH ( ) ETH ETH · 32 ETH ( OK) · 16 ETH ( ) 12 ( ) ( ) 1 — 2025 9-10 — 2025-07-07 – p.31/58
32. / / (5) 32 1 (384 ) ( ) ( ) 2 3 ( ) 256 512 — 2025 9-10 — 2025-07-07 – p.32/58
33. / / (6) ( ) 5 2 3 (36 ) — 2025 9-10 — 2025-07-07 – p.33/58
34. / / (7) ( ) ( ) DAO (RANDAO) 1 — 2025 9-10 — 2025-07-07 – p.34/58
35. Ethereum        ߹ҙ͞Εͨཤྺ ϩʔΧϧʹෳ੡Λҡ࣋ ϒϩοΫ εϩοτ  ඵִؒ  εϩοτͰ  ΤϙοΫ ҉߸ֶతμΠδΣετ ϒϩοΫνΣʔϯͷҡ࣋ࢀՃऀ͕ϩʔΧϧʹ؅ཧ͢Δσʔλۭؒ ࣌ؒ
    ΑΓ৽͍͠ه࿥ ΦϒδΣΫτ τʔΫϯγεςϜ౳ͷεϚʔτίϯτϥΫτ ֤Ϣʔβͷ ࢒ߴ౳ͷঢ়ଶ ঢ়ଶ` ঢ়ଶ`` τϥϯβΫγϣϯ
     ΦϒδΣΫτͷੜ੒ ·ͨ͸ঢ়ଶભҠͷࢦࣔ ແޮͳཤྺ ω ỽ τ ϫ ồ Ϋ Λ ௨ ͠ ͯ ૹ ड ৴ ͞ Ε Δ ϩ ồ Χ ϧ ʹ ࣋ ͭ ܨ͙ͨΊʹ͸
    &5) Ͱͷσϙδοτͱ σϙδοτ૯ֹͷ ♤ ૬౰ͷϢʔβʹΑΔ ΤϙοΫ΁ͷূݴ͕ඞཁ શΦϒδΣΫτͷભҠޙͷঢ়ଶ ͕ϋογϡ໦˞ʹू໿͞Ε ͦͷ ϧʔτ஋͕ϒϩοΫʹॻ͔ΕΔ ঢ়ଶભҠ ˞
    ϋογϡ໦
    
    σʔλ܈ͷ҉߸ֶతμΠδΣετ ϋογϡ ɹ
    Λ໦ߏ଄ʹදݱͨ͠΋ͷͰ
    ෆ੔߹ͷݕग़ʹ༻͍ΒΕΔ ETH ( ) ⇒ ETH = Ethereum Virtual Machine (EVM) 2 3 ETH ⇒ ETH — 2025 9-10 — 2025-07-07 – p.35/58
36. Ethereum (ex. ) (ex. ) ⇒ → — 2025 9-10 — 2025-07-07 – p.36/58
37. — 2025 9-10 — 2025-07-07 – p.37/58
38. 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 ( ) — 2025 9-10 — 2025-07-07 – p.38/58
39. ERC-20 ERC-20 ← ( ) ( ) ⇒ ERC-20 ( ERC-20 ) ERC-20 ⇒ — 2025 9-10 — 2025-07-07 – p.39/58
40. (fungible) ERC-20 → ERC-223 (draft) or ERC-777 ( )( ) (non-fungible) ERC-721 ( ) ( ) ERC-1155 ( ) ERC-3525 (SLOT ) — 2025 9-10 — 2025-07-07 – p.40/58
41. — τʔΫϯ ୅ସ՟ฎ εϚʔτίϯτϥΫτ ݕূՄೳͳঢ়ଶϚγϯ ϓϩϏφϯε དྷྺূ໌
    ୅ସՄೳ ঈؐෆೳ ୅ସՄೳ ঈؐՄೳ ୅ସෆೳ ঈؐՄೳ ୅ସෆೳ ঈؐෆೳ ূ໌͢Δ ಉఆ͢Δ ࢧ෷͍౳ ࠷ॳͷԠ༻ *%
    Χʔυ౳ ηΩϡϦςΟ τʔΫϯ ূ݊ ౳ ηϯαʔ౳ ෺ྲྀɾ Ҩݴॻ౳ อݥਃ੥౳ ௥੻͢Δ ײ஌͢Δ தԝۜߦ σδλϧ௨՟౳ ҭ੒ήʔϜ౳ ൿີ伴Λ࢖͑Δ͔Βຊਓʁ ෛ࠴  Ξηοτͷ ਺஋දݱΛҠసͰ͖Δʁ ొ࿥͞Εͨίʔυͱ ͦͷ࣮ߦϩάͱ݁Ռͷ ਅਖ਼ੑΛ୲อͰ͖Δʁ ݖҖ͕
    Կ͔ͷ಺༰Λূ໌͢Δʁ ࣋ଓ͢Δଘࡏʹ͍ͭͯ ه࿥ΛΞοϓσʔτՄʁ ओମ͕͍ͳ͘ͳͬͯ΋ աڈͷσʔλ͸༗ޮʁ /'5 Ұൠతͳ ೝࣝ ػೳͷ ෼ੳ݁Ռ — 2025 9-10 — 2025-07-07 – p.41/58
42. — 2025 9-10 — 2025-07-07 – p.42/58
43. transfer settle, retrieve asset, retrieve token 3 — 2025 9-10 — 2025-07-07 – p.43/58
44. ( ( )) ( ) / / — 2025 9-10 — 2025-07-07 – p.44/58
45. — 1. ( ) 2. ( ) 3. ( ) — 2025 9-10 — 2025-07-07 – p.45/58
46. token (ERC-20 ) $ brownie bake token GitHub git clone $ git clone https://github.com/ks91/sample-smart-contracts.git sample-smart-contracts contracts, scripts tests token Token — 2025 9-10 — 2025-07-07 – p.46/58
47. 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 — 2025 9-10 — 2025-07-07 – p.47/58
48. (1) from brownie import * import pytest seller = accounts[0] buyer = accounts[1] 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") — 2025 9-10 — 2025-07-07 – p.48/58
49. (2) token.transfer(buyer, 300, {’from’: accounts[0]}) escrow = accounts[0].deploy(OneTimeEscrow, token, buyer, asset, seller, 300) accounts[0]/seller accounts[1]/buyer 300 300 TX buyer seller 300 bake Token 300 ETH wei — 2025 9-10 — 2025-07-07 – p.49/58
50. (3) token.transfer(escrow, 300, {’from’: buyer}) asset.transfer(escrow, {’from’: seller}) assert token.balanceOf(seller) == 999999999999999999700 assert token.balanceOf(buyer) == 0 assert token.balanceOf(escrow) == 300 assert asset.getOwner() == escrow buyer ( ) 300 seller ( ) — 2025 9-10 — 2025-07-07 – p.50/58
51. (4) escrow.settle({’from’: seller}) assert token.balanceOf(seller) == 1000000000000000000000 assert token.balanceOf(buyer) == 0 assert token.balanceOf(escrow) == 0 assert asset.getOwner() == buyer settle() seller OK — 2025 9-10 — 2025-07-07 – p.51/58
52. ( ) — 2025 9-10 — 2025-07-07 – p.52/58
53. 4. (1) × OK (2) 2025 7 3 ( ) 23:59 JST ( ) Waseda Moodle — 2025 9-10 — 2025-07-07 – p.53/58
54. . . . . . . 17 15 (7/5( ) ) ( ) (4 ) (4 ) ( ) (3 ) (2 ) (1 ) (1 ) — 2025 9-10 — 2025-07-07 – p.54/58
55. I — CO2 ⇒ . . . — 2025 9-10 — 2025-07-07 – p.55/58
56. — 2025 9-10 — 2025-07-07 – p.56/58
57. 5. AI (1) AI (a) (b) (c) AI (2) 2025 7 10 ( ) 23:59 JST ( ) Waseda Moodle — 2025 9-10 — 2025-07-07 – p.57/58
58. — 2025 9-10 — 2025-07-07 – p.58/58