Explain like I'm five · Security

What is a VPN?

Virtual Private Network, told as a story about a sealed tunnel from home to the castle.

homeon the road, anyone can peek into my bag

From home to the castle, you take the town road.And on the road, anyone can peek into my bag.

cafefree Wi-FiI can read every letterfree Wi-Fi is a road everyone shares

On the cafe's road, the person next to you sees everything.Free Wi-Fi is a road everyone shares.

home?tunnel mouthcomes out inside the castlesealed

A VPN is a sealed tunnel dug all the way to the castle.Nobody outside can see into it. And you come out inside the castle.

The sealed tunnelnobody sees inside — encryption
The tunnel mouthsits at the castle wall
Out inside the castleyou're treated as castle folk
What the road seesonly that you went underground
the company tunnelhomehome → inside the castlethe personal tunnelcafeexit in another townwhere did he go?cafe → comes out in another town

There are two kinds of tunnel.The company tunnel goes from home into the castle. The personal one goes from the cafe to an exit in another town — the road never learns where I went.

out, and anywhere→ the escortwhich is why the escort to one room is taking over

Out of the tunnel, you can go anywhere in the castle.Which is why the escort to one room is taking over. The tunnel mouth is visible from outside and gets attacked often — and with a personal tunnel, the tunnel's owner sees all your luggage.

In one breath

A VPN = a sealed tunnel from home to the castle. The road can't see in, and you come out inside.

Virtual Private Network. The company VPN (remote access) and the personal VPN (an exit in another town) are the same tunnel used differently. IPsec, WireGuard and OpenVPN are ways of digging. 'Out, and anywhere' is the problem, so ZTNA is taking over.

When grown-ups say it

Encrypted tunnel
The sealed tunnel. Nobody sees inside. → same idea as the sealed box
VPN gateway
The tunnel mouth. The doorway at the wall. Visible from outside, so often attacked. → the escort story
Remote-access VPN
Home → castle. The company tunnel: someone working outside gets inside.
Site-to-site VPN
Castle ↔ branch. A tunnel between two buildings that stays open all the time.
Consumer VPN
An exit in another town. The road can't see, but the tunnel's owner sees everything.
Protocol
How the tunnel is dug. IPsec, WireGuard, OpenVPN. WireGuard is the fast one these days.
Split tunneling
Tunnel only for the castle. The market by road, the castle by tunnel. Faster, but less is sealed.
ZTNA
An escort instead of a tunnel. To one door, not into the castle. → the escort story
Next story
The Errand Runner →
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