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Last Updated 2014-03This Activity and Discussion will outline how internet proxies work to disguise IP addresses, moving through three different scenarios: traffic routed over HTTP, traffic routed through a VPN, and traffic routed over the Tor network.
You can “amplify” this activity by bringing in elements from How Does Email Work? [LINK] if you feel bringing in more routing elements won’t interfere with the basic concepts below.
Have participants gather in a U-shape, a circle, or any suitable shape that permits them to still be able to see everyone else in the room. Hand each participant a numbered post-it to wear on their shirt. Assign someone to be a Sender of a message and a Recipient:
With a pen or marker, write the name of the Recipient on the piece of paper and hand this to the next person in line. Ask them to hand it on down the line until the paper reaches the Recipient:
Using the same piece of paper again, place it inside one of the small envelopes (representing a VPN) and write the number of a participant who is in the middle of the ‘chain’. Hand the envelope to the person closest to you and ask them to “send” the message down to the person with the number you have chosen (the person should be several “steps” away).
Explain that a VPN is like a “tunnel” with an exit point, and that exit point is usually a server at a point where the pages are being requested.
Place the piece of paper inside one of the small envelopes and, picking at random, write the number of one of the participants on the outside. Place the small envelope inside the medium envelope, this time writing the number of a different participant on the outside.
When the large envelope reaches the participant holding the correct number, ask that person to open only the large envelope and call out the number they see on the medium envelope. Before they pass the envelope on, ask them:
When the medium envelope reaches the next participant, ask them to open only the medium envelope and call out the number they see on the small envelope inside. Before they pass the envelope on, ask them:
When the small envelope reaches the next participant, ask that person to open it. Before they pass the piece of paper to its final destination, ask them:
At this point, explain that this is a very simplified representation of how the Tor network can help us reach blocked websites while also making it difficult for people on the Internet to determine where we are located.
Ask participants to describe their observations about how the message was sent in each demonstration.
Participants may observe issues like: having to know where final recipient is, but path can be random and non-sequential; at any point along the journey of the message being sent the message could be seen; etc.