Information Technology Reference
In-Depth Information
what you type, so that copy could be accessed by someone
else? (Any program you run will have access to your files,
of course, because you are the one running it, and you cer
tainly can access your own files.)
b.
In a related matter for a program with several users and
printers, when you ask the machine to print some informa
tion, how do you know that the operating system or the
print procedure does not make a copy at the same time,
perhaps printing the copy on another printer?
c.
If you buy new software for your personal computer (per
haps you purchased a new word processor, spreadsheet, or
video game), how do you know that the diskette containing
the software does not contain a virus? (Some commercially
available packages have been contaminated in the past.)
d.
If you use a virus checker on your own personal com
puter, how do you know that it works as claimed? More
generally, how do you know any software package does
what it claims? How can you be sure that something odd
will not happen when the package is run a certain number
of times?
e.
When you log on to a large computer system, how do you
know that the operating system is not displaying your pass
word to someone else? How do you even know that the
login process is genuine (i.e., not being simulated by some
other program that is designed to capture your password
or to copy your files)?
f.
When you call a service or repair company, how do you
know that the person who comes to your business has not
attached a wiretap to your data communication lines?
g.
In a bank environment, how would you detect if a pro
grammer in the computing department had added a piece
of code that would allow his or her account to be over
drawn? Similarly, in computing interest to the nearest
cent, how would you know that any extra fractions of a
cent were not credited to the programmer's account?
(This latter event has happened, where the total amount
of interest accumulated checked out correctly, but the
programmer became rich by getting thousandths of frac
tions of a cent daily whenever interest for any account
was computed.)
