Ethereum Address Checksum

Ethereum addresses are 42 characters long (0x + 40 hex digits). EIP-55 introduces a checksum by capitalizing certain letters based on the address's hash.

How It Works:

1. Take the lowercase address (without 0x)
2. Hash it using Keccak-256
3. For each character in the address:
   • If it's a letter and hash digit ≥ 8: uppercase
   • Otherwise: lowercase

Examples:

Why It Matters:

• Detects typos in addresses
• Reduces risk of sending funds to wrong address
• Backward compatible (all-lowercase still works)
• Supported by most modern Ethereum wallets