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Operating System




                    Notes          it. In addition to these technical aspects, the conceptual reach of computer security is broad and
                                   multifaceted.
                                   Computer security touches draws from disciplines as ethics and risk analysis, and is concerned
                                   with topics such as computer crime; the prevention, detection, and remediation of attacks; and
                                   identity and anonymity in cyberspace.
                                   While confidentiality, integrity, and authenticity are the most important concerns of a computer

                                   security manager, privacy is perhaps the most important aspect of computer security for
                                   everyday Internet users. Although users may feel that they have nothing to hide when they
                                   are registering with an Internet site or service, privacy on the Internet is about protecting one’s
                                   personal information, even if the information does not seem sensitive.
                                   Because of the ease with which information in electronic format can be shared among companies,
                                   and because small pieces of related information from different sources can be easily linked
                                   together to form a composite of, for example, a person’s information seeking habits, it is now
                                   very important that individuals are able to maintain control over what information is collected
                                   about them, how it is used, who may use it, and what purpose it is used for.




                                       Task    System security is a major problem in this era. Discuss some important security
                                     techniques for operating system.


                                   11.2 Security Problem

                                   System security can mean several things. To have system security I need to protect the system
                                   from corruption and I need to protect the data on the system. There are many reasons why these
                                   need not be secure.
                                   1.   Malicious users may try to hack into the system to destroy it.
                                   2.   Power failure might bring the system down.
                                   3.   A badly designed system may allow a user to accidentally destroy important data.


                                   4.   A system may not be able to function any longer because one user fills up the entire disk
                                       with garbage.

                                   Although discussions of security usually concentrate on the first of these possibilities, the latter
                                   two can be equally damaging the system in practice. One can protect against power failure by
                                   using un-interruptible power supplies (UPS). These are units which detect quickly when the
                                   power falls below a certain threshold and switch to a battery. Although the battery does not last
                                   forever-the UPS gives a system administrator a chance to halt the system by the proper route.
                                   The problem of malicious users has been heightened in recent years by the growth of international
                                   networks. Anyone connected to a network can try to log on to almost any machine. If a machine is
                                   very insecure, they may succeed. In other words, you are not only looking at our local environment
                                   anymore, I must consider potential threats to system security to come from any source. The fi nal
                                   point can be controlled by enforcing quotas on how much disk each user is allowed to use.
                                   You can classify the security attacks into two types as mentioned below:


                                   1.   Direct: This is any direct attack on your specific systems, whether from outside hackers or
                                       from disgruntled insiders.
                                   2.   Indirect: This is general random attack, most commonly computer viruses, computer
                                       worms, or computer Trojan horses.




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