how a VPN works.
VPN stands for Virtual Private Network and is a way in which you can connect to the Internet whilst keeping your web browsing private.
Whenever you go onto the 'net, companies and businesses are watching your every move. The websites you visit, the files you download, it's all being logged and recorded by someone. At least half a dozen companies will have noted that you're reading this article right now.
Google, Bing, Facebook, your ISP, Uncle Tom Cobbly and all. They're watching.
And this raises real concerns about personal privacy. Which is where virtual private networks come in.
By using a virtual private network, you can protect your personal privacy, but just how do they work?
In this guide, I'll show you how a VPN works.
There is a companion page for this article Do You Need a VPN
how a VPN works.
To understand how a VPN works, let's look first at what happens when you connect to the Internet without using a VPN.
When we use the Internet, we simply click on a link to a webpage, and after a brief pause, the webpage appears on our screens.
And it's tempting to think of the Internet as being rather like TV or radio, in that it's being broadcast constantly.
But that's just not the case. The Internet works very differently.
When you click a link to go to a web page or website, for example, let's say this very website, athomecomputer.co.uk
Your computer sends out a request for the webpage in question.
The request goes through your ISP (the company that provides your Internet services), then through what's called a DNS server (which is simply a computer on the Internet).
That "request" for a webpage bounces around the 'net until finally, it arrives at the correct website, my website in our example.
My website processes the request (basically it finds the particular page you want) and then sends that page back.
The web page is sent to the DNS server, which sends it on to your ISP, which sends it to your computer, which then displays the webpage on your screen.
So it's a series of hops, if you like, from one computer to another, outward and then back again.
Each server (computer) that the request travels through can see which webpage you've asked for.
They'll record, or log, your IP address (we'll talk more about IP addresses a little later) and the webpage you requested. The webpage you're looking at.
To give a very simplistic analogy, imagine you're on your hols and you send me a postcard.
"Having a great time, wish you were here etc".
That postcard will travel through several post offices, plus the postmen and women that will deliver it.
They can all see that you're on your holidays, probably be able to tell where you are from the postmark, and they'll be able to read the message you've written to me.
And we all know that, so we don't write anything sensitive or private on a postcard.
If you needed to send me a private message, something for my eyes only, you'd send me a letter.
You'd put the message inside an envelope.
That way, the post offices can only see where the letter was posted, and where it's going.
They can't see the contents of the letter. It's private. It's kept hidden by the envelope.
And that's pretty much what a VPN service does.
It works to hide the webpage or website that you've requested. And it also hides your IP address.
how a VPN hides your online activities
So now we'll use the exact same example, athomecomputer.co.uk, but this time, we'll see just how a VPN works.
On your computer, you have to start the VPN service and wait for it to connect to its servers. This only takes a few seconds.
In connecting to its servers, the VPN service creates a direct connection, over the Internet, from your computer to those servers.
The connection does run through your ISP's computers, that's true, it has to. But they still won't be able to see which websites you're visiting, as you'll see.
So your computer sends out a request for the athomecomputer homepage.
But before the request is sent, it's encrypted, it's scrambled so that it doesn't make any sense. It's a complete unintelligible mess.
Then the encrypted request is sent straight to the VPN servers.
The request for the athomecomputer homepage does pass through your ISP's servers, but they can't read or understand what's in the request.
It's rather like our letter in an envelope analogy earlier.
They can see where the request came from, ie your computer, and they can see where it's heading, the VPN servers, but what the request is for is anyone's guess.
They simply can't read the message.
You'll often see this effect referred to as tunnelling by VPN companies in their advertisements. The data is passing through an encryption tunnel that leads straight to the VPN servers. No-one on the outside of the tunnel can see inside.
at the VPN servers.
When your request gets to the VPN servers, they go to work decrypting it. They unscramble the message so that they can read it.
They need to know which webpage you're looking for.
So sticking with our example, we're looking for the athomecomputer homepage.
Once the VPN server has decrypted your request, it then sends out a request for the webpage your looking for, in our example, athomecomputer.co.uk.
The request is open and unencrypted. It's just a standard request for a webpage.
The request will travel through the VPN company's ISP computers, through a DNS server and finally lands at my website. My website then sends the requested page back through all the same servers.
And all the time, everything is being logged and recorded just as it was earlier.
The difference is that this time, it's the VPN that is looking for the webpage, not you.
It's rather like sending a friend to the shops to pick something up for you.
The shop keeper obviously knows what your pal is buying. Your friend may even be recorded on CCTV buying that item.
But no-one knows that the item is actually for you.
Even if your friend has to show ID or fill in a form of some kind, the item is only traceable to them, not to you.
And that's what the VPN is doing, every website you visit can be traced back to the VPN servers (computers), but that's as far as the trail goes (or that's as far as it should go, we'll come back to this later in VPN Log Files).
Once the webpage you want has reached the VPNs servers, it's encrypted.
The encrypted webpage is then sent to your computer where the VPN software decrypts it and it can be displayed on your screen.
And yes, the webpage does pass through your ISP's servers on it's way to your computer, but because it's encrypted, the ISP has no way of knowing which webpage you're looking at.
In fact, the ISP doesn't know if you're looking at a webpage, a video a picture or your downloading something.
All they can see is a scrambled data packet that needs to be delivered to your PC.
about IP addresses - how a VPN works.
You may already know something about IP addresses, but for those that don't, here's a very quick guide.
Every computer that is connected to the Internet gets an IP address. Something like 220.127.116.11 or 168.212. 226.204. It's similar to a phone number.
When you call someone on your phone, they can see your phone number, and they could keep it. You've probably done it yourself.
When your computer connects to another computer over the Internet, it leaves behind its IP address.
That IP address can be traced back to your computer, in much the same way as a phone number can be traced.
But when you're using a VPN service, the IP address that a website sees is the IP address for the VPN servers, not your computer's IP address.
That's because your computer hasn't connected to the website, the VPNs computers did. So it's their IP address that is recorded.
VPN log files.
When you connect to your virtual private network service, your IP address and login credentials are recorded in the VPN logs.
Everything that you do over the Internet is also recorded in the log files. Every website you visit, video you watch or file you download, it's all recorded in the log files.
So the question then, is, how long does the VPN service keep these log files? Because the logs are the only record of your online activities.
Different countries have different laws regarding the amount of time that VPNs have to keep their log files for.
Now for most of us, that's not really going to be an issue, since VPN companies generally only reveal their logs to law enforcement agencies. And since we're not doing anything illegal, all we're doing is trying to protect our privacy, we don't really have anything to worry about there.