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Anonymity on the Internet
Let's write a letter...
Lets write a letter to a long lost friend across the country. Lets hope to meet up with them again, you've written the letter. Now what? Well, make sure you have (1) Written your address in the top right hand corner of the letter. (2) Written their address on the envelope.
Had you not done (1) or (2) above, something bad will have happened. Without (1), your friend will have enjoyed your letter, but would have had no way of responding. Without (2) your letter would never have reached your friend.
Next you put your letter in the postbox. The postman will then come and take the letter from the box, and take it to his sorting office. In the office, local letters and national letters will be split according to the city, or the first 2 letters of the postcode. Your letter will be put with the national letters, and put onto a van or train and sent to the next office. Once there, it will be examined once again, put into the correct pile, and then moved to the correct area by examining the next parts of the postcode, until it finally reaches your friend.
Your friend reads the letter, looks at your address, writes their reply, and posts it, and the process is repeated in reverse.
In the above, your letter could have been read at anytime by any postman handling the letter, or anybody with access to the postbox, or any point along the way. Had the letter been read, your address will have been given away. You could have left your address out to avoid this, but then you would never have hoped for a reply from a friend.
The Internet - Addressing
When you send data over the internet, you almost certainly want a reply in form of some other data, for example you send your request for google.com, you expect google to display in your browser. For this purpose, your data must be addressed to google, and contain your address for replying. Without one of these, your request is useless.
Sending the data
When you send the data, it goes through a process much similar to your snail mail. Your request for google.com from your house in the UK is going to involve that data going from your computer, to a computer in the USA. Does your computer have a direct cable connection to google.com in the USA? No.
Your data is routed by routers along the way. First, you DO have a connection to your ISP, and so the data goes from your computer to your ISP. They might have a connection to the recipient, but might not. If they dont, they have a connection to a router, that will be 1 step closer to the recipient. Like the postcode was examined in your snail mail, your internet protocol address, your IP Address, is examined, the router knows where to send the data based on this. This process continues over a number of hops, typically between 10 and 20.
As can be seen from the above process, your data not only had to have your IP address in it, it went through several routers/ISPs on its way. Anybody with the capability of listening in to these lines, could read whatever was in there. For this reason, we have things like SSL which encrypt sensitive data such as passwords and credit card numbers to prevent this, but this comes at a cost, which is why we dont do it for most data.
Logging for security
Most servers hope to be secure. For that reason, they record addresses that connect to them, just in case they need to trace a problem later. Servers have always done this, for security or trouble shooting. It's nothing special, it needs no special software, its just a simple process, write the address, available in all data packets, to a file, thats it!
Below is an extract from my website hit logs, stored for upto a month in order to troubleshoot
and trace potential abuse. The number on the left is the sending IP address.
Want to view the journey your data takes?
You can view how many computers your data passes through on its way to the recipient. The
traceroute command will show you this. To run the trace route program from within Windows,
go to start, run. Type cmd. Press OK. You know have a command prompt, type tracert followed
by the name of the website you wish to trace a route. For example:
And press return. You will see a list of addresses some rubbish data passed through on its way to google.com.