VPN Explained - How It Protects Your Privacy Online

About 2 min read

A VPN (Virtual Private Network) is a technology that builds an encrypted virtual private line (tunnel) over the internet to exchange data securely. Even on untrusted networks such as public Wi-Fi, using a VPN protects the contents of your communication from third parties. It is used for a wide range of purposes, from corporate remote access to personal privacy protection.

The Difference Between a VPN and SSL/TLS

Both VPN and SSL/TLS are technologies that encrypt communication, but the scope of what they protect differs. SSL/TLS encrypts specific communication between a browser and a server (HTTPS), whereas a VPN encrypts all communication from a device through a tunnel. For example, a VPN can also protect the communication of applications that do not support HTTPS as well as DNS queries. On the other hand, SSL/TLS can be used with just a browser without additional software, and it also performs authentication for each website (certificate verification). In practice, it is common to use both together: by carrying HTTPS communication inside a VPN tunnel, double encryption is achieved.

How a VPN Works

A VPN creates an encrypted tunnel between the user's device and the VPN server. Because all communication data passes through this tunnel, its contents cannot be read even if intercepted along the way. Major protocols include OpenVPN, WireGuard, and IKEv2/IPsec. WireGuard is a relatively new protocol characterized by a simple design and fast connections. As of 2024, many VPN services have adopted WireGuard as their standard protocol. By routing through the VPN server, the source IP address is also concealed.

You can systematically learn the details of VPN technology from VPN and network security books on Amazon.

Real-World Use Cases

"While setting up our remote work environment, we migrated from a conventional IPsec VPN to a WireGuard-based ZTNA solution. Connection speed improved threefold, and complaints from users have dropped dramatically."

Communication Path Diagram

Practical Considerations and Pitfalls

When choosing a VPN service, it is important to select one that adheres to a no-logs policy (a policy of not storing communication records). Be cautious, as free VPN services may collect and sell your communication data. A common misconception is the idea that "using a VPN makes you completely anonymous," but the VPN provider knows your source IP and may disclose it if there is a legal request. In addition, a VPN cannot prevent access to phishing sites or malware infections. The security of the VPN account itself is also important, so protect your account with a strong, random password and two-factor authentication.internet privacy guides (Amazon) are also helpful references.