If you’ve ever had to connect to a corporate network while working remotely, you may already be familiar with the technology. In the simplest terms, a VPN creates a secure, encrypted connection between your computer and the VPN’s server. This tunnel makes you part of the company’s network as if you are physically sitting in the office, hence the name. While connected to the VPN, all your network traffic passes through this protected tunnel, and no one in between can see what you are up to. A consumer VPN service does the same thing, but extends that protection to the public.
Think about it this way: if your car pulls out of your driveway, someone can follow you and see where you are going, how long you are at your destination, and when you are coming back. With a VPN service, you are essentially driving into a closed parking garage, switching to a different car, and driving out, and no one who was originally following you knows where you went.
There is a caveat to this metaphor, though: Just as the person who was following you could figure out where you went if he or she happened to be at the supermarket when you got out of the car, there are complicated timing algorithms that can be used to figure out your activity at the exact moment you leave the encrypted tunnel. VPN services, while tremendously helpful, are not fool-proof.
Who Needs VPN?
The protection provided by VPNs has many advantages. First and foremost, you’ll prevent anyone on the same Wi-Fi hotspot from intercepting your Web traffic. This is especially handy for travelers and for using public Wi-Fi networks. VPNs also cloak your computer’s actual IP address, making it harder for advertisers (or spies, or hackers) from tracking you online.
This is just good security, but there are people for whom VPNs are essential. Journalists and activists rely on VPN services to get around government censors to communicate with the outside world. Of course, that may be against the law in countries with strict censorship.
VPNs also let you change your IP address to pretend to be from someplace else, in order to access content that may be restricted on a geographic basis. But Netflix and others are starting to make that more difficult. In our most recent round of testing, several VPN services were blocked by Netflix.
Some services, such as TorGuard, allow P2P file sharing and BitTorrent. Others, like HideIPVPN, will cancel your subscription if you use their servers for file sharing. Be smart: don’t ignore the company’s terms of service. You can’t complain if you get caught.