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Unit 9: System Security

technology enables files to be transparently encrypted to protect confidential data from Notes
attackers with physical access to the computer.
4. The President’s Information Technology Advisory Committee (PITAC): The President’s
Information Technology Advisory Committee (PITAC) was established in February
1997, to provide the President, OSTP, and the federal agencies involved in IT R&D with
guidance and advice on all areas of high-performance computing, communications, and
information technologies. Representing the research, education, and library communities
and including network providers and representatives from critical industries, the committee
advises the Administration’s effort to accelerate development and adoption of information
technologies. PITAC was appointed by the President to provide independent expert advice
on maintaining America’s preeminence in advanced information technology (IT).

5. KeyKOS: KeyKOS is a persistent, pure capability-based operating system for the IBM S/370
mainframe computers. It allows emulating the VM, MVS, and POSIX environments. It is
a predecessor of the Extremely Reliable Operating System (EROS), and its successors, the
CapROS and Coyotos operating systems. KeyKOS is a nanokernel-based operating system.
6. Mandatory Integrity Control (MIC) or Integrity Levels: (or Protected Mode in the context
of applications like Internet Explorer, Google Chrome and Adobe Reader) MIC is a core
security feature, introduced in Windows Vista and Windows Server 2008, that adds
Integrity Levels (IL) to processes running in a login session.

7. Protection: A model of protection mechanisms in computing systems is presented and its
appropriateness is argued. The “safety” problem for protection systems under this model
is to determine in a given situation whether a subject can acquire a particular right to an
object.
8. Secure Sockets Layer (SSL): Secure Sockets Layer (SSL) protocol to create a uniquely
encrypted channel for private communications over the public Internet. Each SSL Certificate
consists of a public key and a private key.

1. How to enable the security of operating system?
2. Give the step of installing antivirus.

9.9 Review Questions

1. Buffer-overflow attacks can be avoided by adopting a better programming methodology
or by using special hardware support. Discuss these solutions.

2. A password may become known to other users in a variety of ways. Is there a simple
method for detecting that such an event has occurred? Explain your answer.

3. The list of all passwords is kept within the operating system. Thus, if a user manages to
read this list, password protection is no longer provided. Suggest a scheme that will avoid
this problem. (Hint: Use different internal and external representations.)

4. Discuss a means by which managers of systems connected to the Internet could have
designed their systems to limit or eliminate the damage done by a worm. What are the
drawbacks of making the change that you suggest?

5. Make a list of six security concerns for a bank’s computer system. For each item on your
list, state whether this concern relates to physical, human, or operating-system security.

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