A guide to proxy servers, the computer systems that relay information between users and networks, and how they can disguise users' online presence
- A proxy server is an intermediate gateway that you can use to exchange information with internet resources and websites.
- A proxy server can help mask or disguise your presence online by hiding your computer's IP address.
- There are many uses for proxy servers, including enhancing privacy, monitoring access to the internet, and accessing blocked resources.
Discussions about proxy servers are often in the context of cybersecurity. That's because, as a general rule, proxy servers are used to mask the location or identity of an end user on the internet.
How a proxy server works
You can think of a proxy server as an intermediary or middleman in the exchange of information online; the proxy is a computer that you connect to and pass all of your internet traffic through.
Every computer connected to the internet has its own unique IP address, which is how another computer can find you. The IP address is the root of how computers can find web pages and other online resources. It also means that under ordinary circumstances, your online activities are easily tracked.
A proxy server, on the other hand, can help mask your identity. When you try to visit a website, for example, the request for that URL goes from your computer to the proxy server. The internet sees the request from the proxy, not from you, and then when the proxy gets the data, it passes it on to your computer.
The internet never sees your computer; it is only aware of the proxy server. If a lot of users rely on the same proxy server, your internet traffic is essentially anonymized.
The main types of proxy servers
All proxy servers are still not alike - there are many different kinds designed for various applications. Here's a breakdown of the most common proxy servers you're likely to encounter:
Anonymous proxy
Perhaps the most common kind of proxy server, an anonymous proxy doesn't pass on the IP address of the originating computer, which essentially makes that computer anonymous. It can help prevent from disclosing the location or identity of the computer, as well as minimize the release of information that can enable targeted advertisements.
Transparent proxy
A transparent proxy gets its name because it allows traffic to pass between the originating computer and the internet without changing the data or masking the IP address. For example, many businesses use a transparent proxy to monitor the web traffic of its employees without interfering with the data.
High anonymity proxy
A high anonymity proxy works the same as an anonymous proxy, but it also frequently changes its own IP address, making it very difficult for third parties to learn much about the users behind the proxy.
Distorting proxy
A distorting proxy is also known as a gateway proxy. It's so-called because it doesn't just mask the originating computer's IP address, but actively passes on a falsified IP address. This can help the originator to appear to be operating from a different location than is actually the case.
How proxy servers are used
In addition to the various types of proxy servers, there are a handful of reasons why proxy servers are commonly used. Here's a brief summary of the main applications for proxy servers:
Monitor and control internet access. Proxy servers are excellent for allowing organizations to monitor internet usage and block access to specific websites and online resources. They can be used by IT departments in companies to oversee employee productivity or by families to monitor children's internet safety with parental controls.
Privacy. You can mask your location and identity by using a proxy server. By hiding or changing your IP address, you can substantially increase your privacy online.
Security. By encrypting the traffic flowing through a proxy server, the originating computer can substantially improve both the privacy and security of the users. A proxy server can protect against malware and cyber attackers and is especially useful when merging with a Virtual Private Network (VPN), commonly used by companies for security purposes.
Improve internet performance. If a large number of people tend to access the same websites on a regular basis, a proxy server can cache those pages and make it faster and easier for the originating computers to get that data. Large businesses and government organizations sometimes rely on proxy servers to cache internet content for just this purpose. Of course, this can also be a secondary use of the proxy server in addition to monitoring and controlling access.
Access blocked resources. A proxy server can allow originating computers to masquerade as different computers - and more importantly, appear to be located in completely different geographic locales. That means if an originating computer can't usually access certain content (say, streaming a video that's restricted to certain countries), a proxy server can allow the computer to gain access to that video content by making it look like the originating computer is somewhere it is not.
Risks of proxy servers
While there are advantages of using proxy servers, they also carry some risks:
Proxy servers are not necessarily encrypted. You may like the idea of using an anonymous proxy to protect your privacy, but keep in mind that on its own, a proxy server affords limited security because its data isn't necessarily encrypted. Without encryption, it's not difficult for a motivated third party to learn a lot about the browsing activities of anyone using the proxy. The best security combines anonymous proxy with encryption.
Some proxy servers maintain activity logs. Servers maintain activity logs, and that probably includes your proxy server. Your privacy and security is at risk if you don't have control over the server's logs or if the server's operator doesn't have an ironclad policy of not selling or sharing log data.
Free proxy servers are not secure. You may encounter free proxy server services you can use for free or in exchange for embedded ads. Keep in mind that these servers are inherently untrustworthy; not only is the performance unreliable (you don't know how many users are using them simultaneously at any moment), but it's possible the owners can be harvesting and selling your data - literally the opposite of what your intention was. You'd be well-advised to steer clear of most free proxy servers.