Proxy server

Proxy Server

A proxy or proxy server is basically another computer which serves as a hub through which internet requests are processed. By connecting through one of these servers, your computer sends your requests to the proxy server which then processes your request and returns what you were wanting. In this way it serves as an intermediary between your home machine and the rest of the computers on the internet. Proxies are used for a number of reasons such as to filter web content, to go around restrictions such as parental blocks, to screen downloads and uploads and to provide anonymity when surfing the internet.

Why Use a Proxy?

If you are wanting to surf the web anonymously then proxies can provide you with a means to hide your home IP address from the rest of the world. By connecting to the internet through proxies, the home IP address of your machine will not be shown but rather the IP of the proxy server will be shown. This can provide you with more privacy then if you were simply connecting directly to the internet. There are number of proxies that can provide you with service. You can find a list of these simply by typing “Proxy List” into any search engine. There are some proxies which are free and some which charge money, the choice is up to you but we have found that the paid proxies are more reliable, faster and more secure.

Proxy servers have two main purposes:

Improve Performance: Proxy servers can dramatically improve performance for groups of users. This is because it saves the results of all requests for a certain amount of time. Consider the case where both user X and user Y access theWorld Wide Web through a proxy server. First user X requests a certain Web page, which we'll call Page 1. Sometime later, user Y requests the same page. Instead of forwarding the request to the Web server where Page 1 resides, which can be a time-consuming operation, the proxy server simply returns the Page 1 that it already fetched for user X. Since the proxy server is often on the same network as the user, this is a much faster operation. Real proxy servers support hundreds or thousands of users. The major online services such asAmerica Online, MSN and Yahoo, for example, employ an array of proxy servers.

Filter Requests: Proxy servers can also be used to filter requests. For example, a company might use a proxy server to prevent its employees from accessing a specific set of Web sites.           

The operating principle of a proxy server

The basic operating principle of a proxy server is quite simple: It is server which acts as a "proxy" for an application by making a request on the Internet in its stead. This way, whenever a user connects to the Internet using a client application configured to use a proxy server, the application will first connect to the proxy server and give it its request. The proxy server then connects to the server which the client application wants to connect to and sends that server the request. Next, the server gives its reply to the proxy, which then finally sends it to the application client.

Example of How a Proxy Server Work

Figure 1) Two computers, connected through a third computer (shown in red) acting as a proxy, communicate with each other (shown in grey).

The drawing of Alice (client computer), Proxy, and Bob (web server) shows how a proxy server theoretically works. Alice can relay questions to Bob through the proxy server using the proxy server’s IP address without having to contact him directly. Bob, from his perspective, thinks he is communicating directly with the proxy.

In practice, not all web proxies are created equal. There is a huge variance in how a web proxy can be set up and its technical capabilities. Decoding how a web proxy provides clients with enhanced privacy and security primarily depends upon how the individual proxy handles the individual data packets (the information postcards of the Internet) traveling between Alice and Bob, use of encryption techniques, and the intent of the proxy owner.

Here are three basic communications that a web proxy server might communicate with the users:

1. What is the current time?
   The web proxy takes the message from Alice, and adds its own IP address to the network section of each data packet from Alice. This additional information functions like a postcard that has had a new return address stuck on top of the old. Bob gets a message sent from the new IP address, his response goes to the proxy, and then sends the message on to Alice.
   A shielded IP address from a web proxy may be sufficient for computer users to get around some site restrictions on content. For example, someone in Europe visiting a US site that limits access to computer users with an American IP address can access the site with a shielded IP address from the web proxy.
   However, site access is different from security. If proxy communication with the site is not encrypted with HTTPS protocol, data packets can still be easily dissected to uncover the original user's IP address.
2. Alice had me to ask you “what time is it?”
   Some web proxies will not cover up Alice's address. Similar to a “Forward to” note on a letter, they can add their IP address to data packet headers as HTTP_FORWARDED or HTTP_VIA without covering up the original IP address. For those wanting to shield their IP address and their identity, this is an incomplete solution.
   As the name suggests, for most proxy servers, the IP address is only shielded for web browser activities – not for other connected online apps. Skype VOIP, as just one example, collects and can broadcast a user's real IP address.

By definition, web proxies are well placed to filter and restrict content. They are also positioned to read unencrypted messages and to keep logs of who is sending messages to where. With the unencrypted HTTP protocol, data packets are open postcards that can be easily sniffed out and read – even if the users' IP address has been shielded.

Web proxies also provide limited security to users because they are not technically structured to warn users if data packets have been altered during transit or to certify that only Alice and Bob are in a secure, point-to-point conversation. While some web proxies may include encryption, it is not a guaranteed element.

For consumers wanting to surf the Web privately and securely, a better solution is a VPN (virtual private network). A VPNencrypts all your internet communications while hiding your IP address to protect your privacy. What this means is that anyone trying to sniff your traffic will not be able to decipher it since it’s encrypted.