VPN: Tunnels and Encryption Explained

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VPN: Tunnels and Encryption

A VPN (Virtual Private Network) builds an encrypted tunnel between two endpoints — over a public network like the internet.

How it works

Data is encrypted before sending and wrapped in a tunnel protocol. The remote endpoint decrypts and forwards it to the target network. Outsiders only see the tunnel, not the content.

Protocols

WireGuard: modern, fast, minimal (kernel-integrated, ~4000 lines of code).
OpenVPN: established, flexible, runs on UDP/TCP 443.
IPsec: standard for site-to-site and mobile access (IKEv2).

Use cases

Remote work: secure access to internal systems.
Site-to-site: connect branch offices.
Privacy: securing public Wi-Fi.

Pitfalls

A VPN is not anonymization per se — the VPN provider sees your traffic. Split tunneling routes only specific networks through the tunnel and saves bandwidth.