VPNs: how they work and when to use one
Encrypted tunnel, hidden IP, public wifi: how a VPN works and in which cases it actually protects your connection.
The basic idea
A VPN (Virtual Private Network) creates an encrypted tunnel between your device and an intermediary server: all traffic goes through this tunnel before reaching the Internet. Two main effects:
- Your ISP (and any public wifi) only sees encrypted traffic to the VPN server, not the details of what you're browsing.
- The sites you visit see the VPN server's IP address, not yours.
What a VPN actually protects
| Situation | Is a VPN useful? |
|---|---|
| Unencrypted public wifi (café, airport) | Yes — protects against interception on that local network |
| Hiding your IP/approximate location from a site | Yes |
| Bypassing a geographic restriction | Yes, with contractual limits depending on the service |
| Protecting against malware already installed | No — a VPN encrypts transport, not content |
| Total online anonymity | No — the VPN provider itself can see your traffic |
A VPN shifts trust: instead of trusting your public wifi, you trust the VPN provider, who can technically see your unencrypted traffic (HTTPS excepted, already encrypted end-to-end). Choosing the provider matters as much as using a VPN at all.
VPN vs. HTTPS
HTTPS already encrypts the connection between you and the site you're visiting, end-to-end — a VPN adds another layer of encryption up to the VPN server, most useful on an untrusted local network, but redundant with HTTPS for the privacy of the content itself.
Common protocols
| Protocol | Reputation |
|---|---|
| WireGuard | Modern, fast, small and audited codebase |
| OpenVPN | Long-proven, widely supported |
| IKEv2/IPsec | Good stability on mobile (network switching) |
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