Dealing with Anonymity

Have you ever tried seeing an error when trying to browse through a certain website? It somewhat looks like this:

“ERROR"

The requested URL could not be retrieved.

The following error was encountered: Access Denied.

Access control configuration prevents your request from being allowed at this time. Please contact your service provider if you feel this is incorrect.”

This could be some sort of content-filtering web proxy that is commonly used in organizations like schools and offices to ensure that users conform to the acceptable policies of Internet usage.

Proxies are being used for indirect requests between clients and other servers to ensure anonymity. A proxy server is a computer system that acts as a middleman for requests from entities that seek resources from other servers.

The two main purpose of a proxy server are: to keep the machines accessing it anonymous; and to improve transfer speed access to a resource via caching. Proxy servers do not only hide information (Internet Protocol address or IP address) but also remove traffic such as: cookies, pop-ups, banners, scripts, and/or referrer information. These, however, depends on how a user would configure his proxy settings.

Based on the Figure 1-1, Web Browser sends requests to Web Server through Proxy Server. The response of Web Server to the request of Web Browser is sent back through Proxy Server. Thus, Proxy Server serves as the middleman for both entities. Web Server does not know Web Browser; it only knows Proxy Server. With this, anonymity of Web Browser is kept.

Since a proxy server knows the identity of the one directly accessing it, it is therefore, advisable to choose a proxy server that is of known integrity. The risk of choosing a malicious proxy server that records everything being sent like unencrypted logins and passwords is feasible. However, if there are no other options but to use an unknown proxy server, it is therefore, recommended that private information should not be passed through proxy, unless if it is over an encrypted connection.

There are different types of proxy servers each with different functions: caching proxy server, web proxy, content-filtering web proxy, anonymizing proxy server, hostile proxy, intercepting proxy server, transparent and non-transparent proxy server, forced proxy, suffix proxy, open proxy server, reverse proxy server, tunneling proxy server, and content filter.

The most common type of proxy is the web proxy. It focuses on the World Wide Web traffic and is served as a web cache. Content filter is also among those that are widely used in both commercial and non-commercial organizations. In schools and work places where content filtering proxy is used, certain websites are restricted. Tunneling proxy server is also commonly used in defeating the blocking policies being implemented in most work places. This server effectively implements a “bypass policy” allowing the user to view the blocked pages. Caching proxy server speeds up service request through retrieval of page content saved from a previous request made by the same or even another client. This proxy keeps the local copies of the frequently requested resources, thus allowing a significant reduction of upstream bandwidth usage and cost while increasing the transfer rate performance.

Different proxy servers support different protocols. Some support FTP, while others support HTTP only. There are also those that support HTTPS. It is therefore, suggested that users should choose a proxy server that supports protocols, he wishes to use.