Information Technology Reference
In-Depth Information
Internet?
As I noted in Chapter 8, the transmission of information over the
Internet begins with your computer broadcasting one or more packets
of data on your local Ethernet cable en route to the Web server.
Because you use public cables to transmit data, you cannot be confi
dent that your data are entirely secure. Nearby computers listen to
these Ethernet cables and could potentially read the data you send. If
the destination of your communication is beyond your local network
segment, then those packets are forwarded from one server, bridge, or
router to another, as your data move from one segment to the next,
eventually reaching the desired destination. Altogether, this segment
tosegment movement of information implies that each packet of data
might be read by dozens or hundreds or even thousands of computers.
In most processing, each computer on this path either ignores your
data (as not being intended for it) or forwards your information to the
next location; computers en route normally do not examine or analyze
your data. From this standpoint, you might think information trans
mitted through the Internet seems reasonably secure.
However, because your information is sent on many segments,
there always is the potential that some computer on some segment
will copy, analyze, store, or otherwise process the information, even
if all other computers ignore it. For example, a program on an in
termediary computer might be programmed to look for sequences
of characters that could be creditcard numbers, recording each
such sequence of digits. The interconnection of computers provides
an opening for message monitoring, and the capabilities of modern
computers could easily provide a snooping program with the ability
to review a massive amount of information. Although the likelihood
may be reasonably low, the cost of such an information interception
could be quite high, and it is best to assume that data in any packet
are susceptible to being read by an unauthorized party.
Of course, some data you send may have little value to anyone
else. Someone might intercept your request to view a Web page, but
you are unlikely to care if someone discovers that you went to a Web
page to purchase a book; find information about Grinnell, Iowa; or re
view a flight schedule. These Web sites are publicly known, and the in
formation they contain is not secret.
