This Week I Learned (TWIL): Signature Standards in Ethereum and Diamond Proxies

Let’s dive into two critical EIPs: EIP-191 and EIP-712. They play a key role in making Ethereum signatures more secure, readable, and versatile. 👇

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Why do we need these standards?

✅ Human-readable messages: EIP-712 shows structured, user-friendly signing prompts.
✅ Security: EIP-712 prevents replay attacks.
✅ Sponsored transactions: EIP-191 enables sending transactions on behalf of users.

EIP-191: Basic Structure

📜 Format: 0x19<1 byte version><version specific data><data to sign>

Examples of <1 byte version>:
🔹 0x00: Data with a validator
🔹 0x01: Structured data (EIP-712-compatible)
🔹 0x45: Personal_sign

EIP-712: Structured Data Signing

EIP-712 improves traditional message signing by:
🖼️ Adding structure for easier message readability.
🛡️ Defining fields explicitly to prevent signing unintended data.

Let’s break it down! 👇

Key Components of EIP-712

1️⃣ Domain Separator:
It encodes metadata like app name, version, chain ID, and contract address.
It ensures the signature is valid only within its intended domain.


Finally, combine everything:
The signature includes:
0x19 0x01 <domainSeparator> <hashStruct(message)>

This ensures:
🔒 Security
🔍 Transparency for users

EIP-712 = Better UX + Stronger Security 🚀

Diamond Proxy Architecture

Another gem from this week: Diamonds! 💎
They enable modular, upgradeable contracts via EIP-2535. Think of it as:

🏨 A hotel where:
	•	Front desk = Diamond proxy
	•	Services = Facets
	•	Shared resources = Shared storage

Why Diamonds?
💡 Modular: Break contracts into smaller, manageable parts.
🔄 Upgradeable: Update facets without changing the contract address.
🔗 Shared: Centralized storage for all facets.

Smart contract engineering at its best! 🤖

That’s a wrap for this week! 🛠️
Thanks as always to @cyfrin

2️⃣ Hashing the Message:
EIP-712 hashes the structured message to ensure integrity and prevent tampering.