CASE STUDY # 3

In a multiprogramming and time-sharing environment, several users share the system simultaneously. This situation can result in various security problems. Name at least two of these problems. Can we ensure the same degree of security in a time-share machine as we have in a dedicated machine? Explain your answer

Multiprogramming is a rudimentary form of parallel processing in which several programs are run at the same time on a uniprocessor. Since there is only one processor , there can be no true simultaneous execution of different programs. Instead, the operating system executes part of one program, then part of another, and so on. To the user it appears that all programs are executing at the same time.

One problem that could occur is that one user may modify the data which is required by another user. For example, User A is saving a data in the CPU, and User B is browsing some files and unintentionally modified the file that User A is doing, it could ruin the files of which User A is doing and it could end up in a mess. Another example is that when User A is decrypting a data that very important and private, but User B intentionally removes the data or is decrypting also the data at the same time. This could lead into a certain mislead action and is possibly a dangerous one.

Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing. By allowing a large number of users to interact concurrently with a single computer, time-sharing dramatically lowered the cost of providing computing capability, made it possible for individuals and organizations to use a computer without owning one, and promoted the interactive use of computers and the development of new interactive applications. Dedicated Machine is a computer that services one primary function or task. For example, an automobile might have an onboard computer that is dedicated solely to navigation.

As what we know, time-sharing machine is a shared process which different users can access the entire computer in the same time. The more complex it can get the more dangerous and harmful the threats can be on that computer. Unlike in a dedicated machine, one user can only access the file at a time so the lesser will be the harm on the machine.

CASE STUDY # 2

Select two of the following professionals:

• An insurance adjuster
• A delivery person for a courier service
• A newspaper reporter
• A doctor (general practitioner)
• Manager in a supermarket

Put forward a theory about how that person might use a hand held computer in their work.

A portable computer that is small enough to be held in one's hand. Although extremely convenient to carry, handheld computers have not replaced notebook computers because of their small keyboards and screens. The most popular hand-held computers are those that are specifically designed to provide PIM (personal information manager) functions, such as a calendar and address book.

In being a newspaper reporter, information is very important and he/she should have the wide range of knowledge in different kinds of field. He/she should be open-minded and informative of what is happening around the world. As a newspaper reporter, he/she should also have the device in order to keep track of the happenings in the globe or in his/her country. He/she will need a device that could make his/her work much easier than usual. Having a handheld computer can help and do his/her job much easier with a vast range of information in his/her palm. He/she can actually use the device in order to jut down the information’s he/she has taken. With the use of a handheld computer, he/she can easily browse the internet with just one click away on getting the hottest news around the globe. He/she can also use all the applications like video and camera in order to capture some interesting and important events.

As a manager in a supermarket, he/she will be in need of vast range of customers in order to gain clients or investors in his supermarket. He/she will be in need of the news about the prices and increases of goods that he/she is selling into his/her supermarket. Imagine having a supermarket but you don’t have the knowledge about the products that you are selling. It could end up in a bankruptcy. A handheld computer/device can actually save a sinking business with a simple glitch. He/she can use the handheld computer in order to browse the news or the change in prices or even the information’s regarding to which product should sell best. Knowing which the best is or which is not is very important in having a business like running a supermarket. Knowing the most convenient way is the best way to be successful in a business. We, people, should take advantage of what we have right now and make use of it in order to survive in this battle.