IKEv2 (Internet Key Exchange version 2) is a protocol used to set up secure communication channels—especially in VPNs (Virtual Private Networks). It’s like the behind-the-scenes negotiator that ensures both sides agree on how to encrypt and authenticate data.

🧩 What IKEv2 Does

• Establishes secure connections between devices over the internet
• Manages encryption keys and authentication methods
• Works with IPsec to protect data in transit
• Supports mobility, making it ideal for switching between networks (like Wi-Fi to mobile data)

🛠️ How It Works

IKEv2 operates in two phases:

1. IKE SA (Security Association): Sets up a secure channel and negotiates encryption/authentication methods
2. IPsec SA: Uses the agreed methods to encrypt and authenticate actual data packets

It uses Diffie-Hellman key exchange to create shared secrets without transmitting them directly, and supports features like Perfect Forward Secrecy, which frequently changes keys to enhance security.

📱 Why It’s Popular

• Fast reconnection when switching networks (thanks to MOBIKE support)
• Strong encryption and reliability
• Built-in support on many platforms, including Windows, iOS, and Android

🧠 Real-World Analogy

Imagine two spies meeting in a café:

• They agree on a secret language (encryption)
• They verify each other’s identity (authentication)
• Then they start exchanging messages—securely and privately