🗝️ Public/Private Keys Explained Like You're 5

Mailbox others can drop into, opened with your key Day 90 of 149 👉 Full deep-dive with code examples The Mailbox Analogy Imagine a special mailbox in front of your house: People can drop letters through the slot (public key) You use the key to open and read them (private key) Even if attackers intercept the letters, they generally still can’t read them without the private key. How It Works ENCRYPTION: Bob wants to send Alice a secret message 1. Alice shares her PUBLIC key (others can have it) 2. Bob encrypts message with Alice's public key 3. Alice's PRIVATE key is used to decrypt it 4. Attackers usually can't decrypt it without the private key The Magic Public key encrypts → Private key decrypts Encrypt("Hello", Alice's_Public_Key) → "x7$k2!m@" Decrypt("x7$k2!m@", Alice's_Private_Key) → "Hello" Decrypt("x7$k2!m@", Anyone_Else's_Key) → 💥 Fails Real Uses Use How It Works HTTPS Browser uses server's public key SSH Your public key on servers, private on laptop Email signing Sign with priv