Saturday, December 22, 2007

Anonymizers and Remailers !! What n How

Anonymizers and Remailers !! What n How

Anonymizers are online services that eliminate the trail of information that you leave behind, whilst surfing, so that your online activities cannot be traced back to you. The anonymizers vary in sophistication depending on the level of security and number of features that you require. Some anonymizers require the use of client software and others only require that you log onto their website before browsing other sites*.

How do Anonymizers work?

You essentially surf the Web through the anonymizer site, going to that site first and then routing all your pages from there. When you send a page request through the anonymizer, it acts like a super-proxy server, stripping off the header of each data packet, thus making your request anonymous. The requested page is then fed through the anonymizer back to your Web browser**.

In order to avoid being tracked, one can use an anonymous proxy to surf the web. An anonymous proxy makes sure your IP address does not get stored on the web server logs. Web servers log every ?GET? request made, together with date, hour, and IP. But if you are accessing the Internet through a proxy server, then the IP of the proxy is logged and not yours.
In case you do not go through an anonymous proxy, then you are actually risking vital information that belongs to you. For example, a hacker can easily find out your IP Address, your web browser, your Operating System and even the previous URL that you have visited. You can also be easily located geographically (provided one has the necessary software tools) because people can find out a whole lot of things that give your location. Like your hostname, your continent, your country, your city and even your Internet Service Provider.
Consider the scenario where a hacker gets access to your computer, he can find out your name, email address, telephone number, various user ID's and passwords, details about software you use and your preferences, locations of files and folders, the search strings that you used and literally hundreds of other personal things. All this information is stored in files like SYSTEM.ini, USER.dat, SYSTEM.dat etc. One very important file is the nsform??.TMP which stores all the data inside every Netscape form you've ever submitted, with and without SSL, when the submission failed or was cancelled.

What are Re-mailers?

Anonymous Re-mailers are services used to send e-mail messages, so that the recipient of the e-mail cannot determine the identity of the sender. Re-mailers strip off header information leading to the identity of the sender and often route a message through a chain of re-mailers before reaching the recipient. Many re-mailers also include some sort of message based encryption. Re-mailers are commonly used to protect the anonymity if the sender from the recipient, to prevent eavesdropping by a third party, or to post anonymously to newsgroups*.
How do Re-mailers Work?

An anonymous re-mailer is simply a computer connected to the Internet that forwards electronic mail or files to other addresses on the network. It also strips off the "header" part of the messages, which shows where they came from and who sent them. All the receiver can tell about a message's origin is that it passed through the re-mailer. Some re-mailers also allocate each sender an "anonymous ID", rather like a PO Box number, which it stores with the sender's address so that any replies reach them.***

All re-mailers are fairly effective at what they do and some even take an extra step and add encryption to all outgoing messages. In order to view header information sent via email messages in Outlook Express, select a message in your inbox, then select File | Properties | Details.
To view header information in m*c*s*t Outlook, right-click a message in your inbox and select Options; the header information is displayed in the Internet Headers area of the Message Options dialog box.

Anonymous re-mailers were invented by security experts interested to know whether it was possible to send a message on the Internet which could not be traced back to its source. As soon as the first ones were built, though, people found a more pragmatic use for them: to send messages to bulletin boards about subjects so sensitive that they did not want their names known.