Network Security - Virtual Private Network (VPN)

A Virtual Private Network (VPN) is a technology that creates a secure, encrypted tunnel for data transmission over a public network (like the internet). It ensures that sensitive information stays private and protected from eavesdropping or interception.

Purpose of a VPN:

  • Confidentiality: Encrypts data so outsiders can’t read it.

  • Integrity: Prevents tampering or modification of data in transit.

  • Authentication: Verifies the identity of users and servers.

  • Privacy: Masks the user’s IP address and location.

How It Works:

  • A VPN client on the user’s device connects to a VPN server.

  • All traffic is encrypted before leaving the device.

  • The VPN server decrypts it and forwards it to the destination.

  • The return traffic goes back through the tunnel, encrypted again.

Types of VPN:

  1. Remote Access VPN:

    • Used by individuals to securely connect to a private network (e.g., employees working from home).

  2. Site-to-Site VPN:

    • Connects entire networks together (e.g., branch offices to headquarters).

  3. Client-to-Site VPN:

    • A single device connects securely to a corporate network.

Common Protocols:

  • IPSec: Secure, widely used for site-to-site VPNs.

  • SSL/TLS: Often used for remote access VPNs through web browsers.

  • WireGuard & OpenVPN: Modern, secure, and efficient alternatives.

Benefits:

  • Protects data on untrusted networks (like public Wi-Fi).

  • Enables secure remote work.

  • Helps bypass geo-restrictions and censorship.

Limitations:

  • Can reduce internet speed due to encryption overhead.

  • VPN security depends on proper configuration.

  • Trust is shifted to the VPN provider (if using a third-party service).

 

Would you like me to also compare VPNs vs Zero Trust Network Access (ZTNA)? They’re often discussed together as modern secure remote access solutions.