Notes

Great! Let’s break down the Self-Custody Web3 Architecture from the diagram and go into the technical details, including how you can implement each part in a Web3-powered app like KoinBX.

1. Frontend (User Interface)
Description:
Users interact with your dApp through the frontend. It doesn’t hold any sensitive data — all wallet-related actions are triggered here.

Stack:

Framework: React / Next.js (recommended for performance)

Wallet Integration:

ethers.js or web3.js for Ethereum interactions

wagmi + RainbowKit for easy wallet connectivity (MetaMask, WalletConnect, etc.)

Security Libs:

DOMPurify (against XSS)

Zod or Yup for schema validation

Functionality:

Initiate wallet creation or import via mnemonic/private key

Display balances and NFTs (from on-chain data)

Trigger transactions signed locally

2. Self-Custody Wallet Module (On Device)
Description:
Instead of storing keys on a central server, users’ private keys are generated and stored locally on their devices (in secure storage).

Tech Stack:

Key Generation & Management:

ethers.Wallet.createRandom() or BIP39 for mnemonic

Secure Storage (Mobile):

Android: EncryptedSharedPreferences, Keystore

iOS: Keychain, Secure Enclave

React Native: react-native-keychain

Browser:

Store encrypted keys in IndexedDB or localStorage using crypto.subtle

Security Enhancements:

Use a PIN/Biometrics to unlock access to private keys

Optional passphrase-based encryption

3. Blockchain Interaction Layer
Description:
Handles all direct interaction with the blockchain (Ethereum, Polygon, BSC, etc.)

Tech Stack:

Library: ethers.js or web3.js

Provider: Infura, Alchemy, QuickNode (read/write access)

Features:

Sign transactions locally with private key

Send signed transactions to the blockchain

Query balances, NFTs, gas prices

Example (Signing TX):

js
Copy code
const wallet = new ethers.Wallet(privateKey);
const tx = await wallet.sendTransaction({
to: '0x...',
value: ethers.utils.parseEther('0.1')
});
4. Backend (Optional / Minimal)
Description:
No user data or keys are stored on the server. Backend is used for:

Providing metadata

KYC integration

Notifications

Transaction history indexing

Stack:

Node.js / FastAPI

Database: PostgreSQL / MongoDB (for metadata only)

Indexing: The Graph / Moralis / Alchemy SDK

5. Encrypted Backup & Recovery (Optional)
Description:
Allow users to backup encrypted private keys to cloud (e.g., Google Drive, iCloud), but only if they choose to.

Stack:

Encrypt key using AES (with a password or biometric key)

Upload encrypted blob to user’s cloud drive

Libs:

crypto-js, sjcl, libsodium

Cloud SDKs (Google Drive, iCloud via native integration)

6. Security Layer
Security Measures:

End-to-End Encryption: For any backups or communication

2FA (Optional): For sensitive actions (not key-related)

Biometric Auth: Unlock local key vaults

Open-source Verification: Users can verify how keys are stored and managed

Conclusion / Workflow Summary
User signs up & creates wallet → private key generated on device

Keys are stored locally (or encrypted and backed up if user opts in)

User signs transactions using local keys → TX sent to blockchain

Server only provides UI support, metadata, and optional services

Would you like me to now generate a complete PDF document including all this explanation along with the architecture diagram and implementation strategy?







You said:
Yes add it in PDF


ChatGPT said:

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python
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Copy code
from fpdf import FPDF
from PIL import Image

# Define PDF class
class PDF(FPDF):
def header(self):
self.set_font("Arial", "B", 14)
self.cell(0, 10, "Self-Custody Web3 Architecture for KoinBX", ln=True, align="C")
self.ln(5)

def chapter_title(self, title):
self.set_font("Arial", "B", 12)
self.cell(0, 10, title, ln=True)
self.ln(2)

def chapter_body(self, body):
self.set_font("Arial", "", 11)
self.multi_cell(0, 8, body)
self.ln()

# Initialize PDF
pdf = PDF()
pdf.set_auto_page_break(auto=True, margin=15)
pdf.add_page()

# Add the architecture image
image_path = "/mnt/data/A_2D_digital_diagram_illustrates_self-custody_arch.png"
img = Image.open(image_path)
pdf.image(image_path, w=170)
pdf.ln(10)

# Content sections
sections = {
"Frontend (User Interface)": """
Users interact with your dApp through the frontend. It doesn’t hold any sensitive data — all wallet-related actions are triggered here.

Stack:
- Framework: React / Next.js
- Wallet Integration: ethers.js or web3.js, wagmi + RainbowKit
- Security Libs: DOMPurify, Zod/Yup

Functionality:
- Initiate wallet creation/import
- Display balances and NFTs
- Trigger transactions signed locally
""",
"Self-Custody Wallet Module (On Device)": """
Private keys are generated and stored locally on user devices.

Tech Stack:
- Key Generation: ethers.Wallet.createRandom(), BIP39
- Secure Storage: EncryptedSharedPreferences, Keychain, Secure Enclave, react-native-keychain
- Browser: IndexedDB/localStorage with crypto.subtle

Security:
- PIN/Biometrics to access
- Optional passphrase encryption
""",
"Blockchain Interaction Layer": """
Handles interaction with Ethereum, Polygon, etc.

Tech Stack:
- Library: ethers.js or web3.js
- Provider: Infura, Alchemy, QuickNode

Features:
- Locally sign transactions
- Send TX to blockchain
- Query balances, NFTs
""",
"Backend (Optional / Minimal)": """
Backend is used for metadata, KYC, notifications, and history.

Stack:
- Node.js / FastAPI
- DB: PostgreSQL / MongoDB
- Indexing: The Graph / Moralis / Alchemy SDK
""",
"Encrypted Backup & Recovery (Optional)": """
Allows encrypted backup of private keys to cloud storage.

Stack:
- Encryption: AES via crypto-js, sjcl, libsodium
- Cloud SDKs: Google Drive, iCloud

Optional, user-initiated only.
""",
"Security Layer": """
Security Measures:
- End-to-End Encryption
- 2FA (optional)
- Biometric Auth
- Open-source verification
""",
"Workflow Summary": """
1. User creates wallet → keys generated locally
2. Stored securely or backed up (optional)
3. Transactions signed on device
4. Server used for UI and metadata
"""
}

# Add all sections to PDF
for title, body in sections.items():
pdf.chapter_title(title)
pdf.chapter_body(body)

# Save the PDF
pdf_path = "/mnt/data/Self_Custody_Web3_Architecture_KoinBX.pdf"
pdf.output(pdf_path)

pdf_path
It seems like I can’t do more advanced data analysis right now. Please try again later.

If you’d like, I can provide you with all the text content and layout so you can manually create the PDF, or I can guide you on how to generate it using tools like Word, Google Docs, or a local Python script. Let me know what works best for you!