Wallets and Keys
Cryptocurrency wallets don't actually store your coins. Instead, they store cryptographic keys that prove your ownership and allow you to sign transactions. Understanding the difference between public and private keys is essential for keeping your funds safe.
Key Generation Flow
┌──────────────────┐
│ Random Number │ (256-bit private key)
│ Generation │
└────────┬─────────┘
│
▼
┌──────────────────┐
│ PRIVATE KEY │ e.g., 0x8f4a2b1c...9e3d
│ (Secret!) │ Only you should know this
└────────┬─────────┘
│ Elliptic Curve (secp256k1)
▼
┌──────────────────┐
│ PUBLIC KEY │ e.g., 0x04a7b3c2...8f1e
│ (Can share) │ Derived from private key
└────────┬─────────┘
│ Keccak-256 hash + trim
▼
┌──────────────────┐
│ WALLET ADDRESS │ e.g., 0x742d35Cc6634C0532
│ (Can share) │ What you give to others
└──────────────────┘
Public Key vs Private Key
PUBLIC KEY PRIVATE KEY
┌────────────────────────┐ ┌────────────────────────┐
│ Like your email │ │ Like your password │
│ address │ │ │
│ │ │ - NEVER share it │
│ - Share freely │ │ - Write it on paper │
│ - Others send to this │ │ - Store offline │
│ - Cannot spend funds │ │ - Controls all funds │
└────────────────────────┘ └────────────────────────┘
RULE: If you lose your private key, you lose your funds FOREVER
RULE: If someone gets your private key, they own your funds
Types of Wallets
Hot Wallets — Connected to the internet. Convenient but less secure.
Examples: MetaMask, Trust Wallet, Exodus
Cold Wallets — Offline storage. Maximum security.
Examples: Ledger Nano, Trezor, paper wallets
Security vs Convenience:
◄──────────────────────────────────────────►
MORE SECURE MORE CONVENIENT
┌────────┐ ┌────────┐ ┌────────┐ ┌────────┐
│ Paper │ │Hardware│ │Desktop │ │ Mobile │ │ Web
│ Wallet │ │ Wallet │ │ Wallet │ │ Wallet │ │Wallet
└────────┘ └────────┘ └────────┘ └────────┘ └────────┘
Offline Offline Online Online Online
Seed Phrase (Recovery Phrase)
Most wallets generate a 12 or 24-word seed phrase when created. These words can reconstruct your private key. Write them down on paper and store them in a secure location. Never store them digitally or share them with anyone.
Example 12-word seed phrase:
┌──────────────────────────────────────────────┐
│ 1.abandon 2.word 3.alice 4.bike │
│ 5.chunk 6.dawn 7.eagle 8.forest │
│ 9.habit 10.ice 11.jungle 12.kite │
└──────────────────────────────────────────────┘
Anyone with these 12 words can access ALL your funds