A VPN, or Virtual Private Network is a special kind of network in which the data you send over the internet is directed through a secure, encrypted connection that goes through a third party server. You run a VPN client on your machine and that client connects to the VPN server. All data that you want to transmit, and all connections that you make, are first directed through the VPN in a secured and encrypted form.
VPNs are very useful for privacy because all traffic going through them is encrypted. If, for example, you have to use a very old and poorly configured email server for your work email, you may have to send your POP3 and SMTP logins in plain text. When you are using a standard wireless connection, all data transmitted in plain text can be tapped by someone who has the right software. If you first send your data through the VPN, it would be encrypted so basic eavesdropping techniques (such as wireless packet snooping) would not work.
Keep Intruders in the Dark
VPNs are useful for security and privacy because they can stop intruders from knowing which servers you are connecting to and what data you are transmitting. Techniques such as DNS spoofing or ARP poison routing, which can be used to trick your computer into thinking that they are connecting to a different server, are also less likely to be effective, because once you are connected to the VPN, all other connections will go through that so they will not be vulnerable to such crude attacks.
That’s not to say that VPNs are completely secure – a determined attacker could find other ways to access the information that they are looking for. However, many attackers – especially those operating in public coffee shops, are simply looking for a low hanging fruit. If you don’t pose an obvious target, they will ignore you and move on.
Other Effective Tools
There are many other tools that you can use to improve your internet security. Everyone should have a good firewall, antivirus, antimalware and an email client with effective spam filter. It is also worth considering locking your computer and not storing your passwords in your browser. If you must keep your passwords, consider doing so in a program such as LastPass, which will encrypt the passwords for you.
Privacy and security are two things that you must take very seriously. Secure your personal data, so if you are going to focus on privacy, make sure that you take a privacy-centric approach from the ground up. There is no point choosing good passwords and using a good firewall and a VPN if you then leave your laptop open and unattended in a public place. Remember that sometimes it is physical access to your computer that causes the greatest security threat. Overlooking such simple things could be the undoing of your security policy.