Information Technology Reference
In-Depth Information
software, but such troublesome programs may be found from
time to time on commercial software. Of course, you have lit
tle control at all over software you download over the Web,
so you need to be particularly cautious before installing any
new programs onto your system. (The first virus file I ever re
ceived was in email sent inadvertently by the director of a
statewide organization related to the computing industry.)
Expanding on these last two points, programs obtained from
others may have wonderful capabilities, but they also might have
“features” that undermine the security on your computer. Further,
if you download a program and then run it, the program likely has
full access to all of your materials—after all, you have chosen to run
the program from your account, and therefore have responsibility
for any work done on your account.
Outside of monitoring what programs you download, having
antivirus software, using passwords, and creating firewalls, you
should carefully monitor what permissions you grant to each of
your files. For added security, you can separate public and private
files into separate directories to help avoid inadvertent relaxing of
permissions. If you place private files in your private directories,
then permissions must be relaxed for both a directory and a file in
that directory before outsiders can view the information. Although
mistakes still can happen, protection via two permissions is gener
ally more secure than protection based on only one permission.
network compromise its security?
In principle, firewalls, password protection, antivirus software,
and the like should provide reasonable security for your machine
when it is connected to the Internet. And, of course, no processing
whatsoever occurs if the machine is turned off, so we only need to
discuss risks if the machine is turned on.
In practice, however, operating systems and other programs are
quite complex, and thus prone to containing errors that in turn
could create vulnerability and allow someone to access your com
puter through the network. Vendors of operating systems (such as
