In a multiprogramming and time-sharing environment, several users share the system simultaneously.?

Question

This situation can result in various security problems.
a. What are two such problems?
b. Can we ensure the same degree of security in a time-shared machine as we have in a dedicated machine? Explain your answer.

Answer 1

Another homework question. It's probably in your book. :)

I'm sure the answer to (a) is in the book already.

As for (b) note that even in the case of dedicated processing, you *still* have security issues (most notably, physical access issues (repairmen, etc), and sanitizing media upon system decommission.

In *real* computer security (as opposed to what's in your textbook, apparently), the answer to (b) is "No, it's not as secure, but who cares". The *real* question is "How much less secure is it, and does the added exposure outweigh the cost savings *for this application*. If you're working with nuclear launch codes, it's going to be hard to argue for saving money by timesharing. If it's just a bank's database, timesharing makes sense (and you get *added* security there because you can have one guy update software for patching and *everybody* is running the new software, rather than having 1,000 desktops not all of which are patched).

A case can be made that to secure a system, mutli-user operation is required, in order to support multiple roles (sysadmin, security auditor, and user) - dedicated operations don't provide a suitable audit trail.

Also, it's the rare multiprogramming system these days where the operating system is the weak link - even Windows provides enough security that your biggest threat is idiot and malicious users.

Answer 2

i do not know, please give the answer atonce.