At every step, somebody might be trying to intercept your data.
22 The Problem
type an address in a browser on a machine at the workplace,
our request will go through some networking hardware (a
switch or a hub), and then it will jump from computer to computer
in our intranet until it reaches our Internet service provider
machines. From that moment on, our data packets zigzag
through a path of intermediary machines that is very dif?¬?cult to
predict, eventually (in most cases) reaching the machine that
corresponds to the address we originally typed in the browser. It
is possible to measure this phenomenon; a simple query for
traceroute on any search engine will return a list of utilities that
will show (even on a world map) the path followed by packets
from the origin computer to any website.
You might be tempted to think that once the information is
transmitted on the network, it becomes unreadable gibberish
(???signal???) until it reemerges from the other side of the cable;
think again. The reality is that unless you take some special
measures, what is sent on a network is as clear as a text ?¬?le. The
only difference is that while a ?¬?le sits on the disk for as long as it
is needed, if somebody wants to read network traf?¬?c he has to
do it while the transmission takes place.
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