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.

Technology has become the fastest growing environment here on earth. One concrete example of that technology is the computer. Computers or human-like machines have actually contributed to the development of the world. As technology arises, more and more machines are being developed. From a single user gear into a multi-user and multiprogramming processes. These things help us do multiple tasks in work, studies, and interests.

But then problems would never fade away. They would always arise. And as these things are continually growing, more and more problems are still increasing.

Things like this happen also in a multiprogramming and time-sharing environments. Some situations like having different users at the same time may result to various security problems

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But first, let us discuss what is multiprogramming and time-sharing?

In using computers, multitasking is a method by which we perform multiple tasks also known as processes at the same period of time and share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for that task. Multitasking solves the problem by scheduling which task may be the one running at any given time, and when another waiting task gets a turn.

In order to achieve the tasks performed by a single CPU, there are different scheduling strategies so that the jobs will be performed.

In multiprogramming systems, the running task keeps running until it performs an operation that requires waiting for an external event (e.g. reading from a tape) or until the computer's scheduler forcibly swaps the running task out of the CPU. Multiprogramming systems are designed to maximize CPU usage.

In time sharing systems, the running task is required to relinquish the CPU, either voluntarily or by an external event such as a hardware interrupt. Time sharing systems are designed to allow several programs to execute apparently simultaneously. The expression 'time sharing' was usually used to designate computers shared by interactive users at terminals.

One of the security problems that would happen is when he would copy some of your files, delete or change it.

 An example is when the other user may overwrite your files. This would occur at some point when you already finished the first job and you are now working with your second job, but the other user had already finished the job that you are currently doing and is starting to work with your first job, this thing may lead to mixing of programs and result to error. This may also corrupt your files and would let you start your job all over again. This kind of state may lead to a failing work, unfinished jobs and damaged files and lesser memory.

The other user of your system may copy some of the files or programs and/or memory space you have. If he found a folder in your system that he might use in some other time, he would have a duplicate with it and make use of it in other instances.

The other user may also delete or accidentally delete the files you have most especially when he would think that he will never need it anymore.

The second problem is the sharing of your systems resources that may result to deficient memory.  As we all know multiprogramming is a technique that allows a single processor to process several programs residing simultaneously in main memory and interleaving their execution by overlapping I/O request with CPU request. It attempts to increase CPU utilization by always having something for the CPU to execute. The system switches among the programs for efficient processing and minimal idle time.    

When multiple programs are present in memory, an ill-behaved program may (inadvertently or deliberately) overwrite memory belonging to another program, or even to the operating system itself.

Can we ensure the same degree of security in a time-share machine as we have in a dedicated machine?

A time-share machine allows multiprogramming processes and multi-tasking at the same time. One example of this is the personal computer and laptops. They are skilled to do multiprogramming skills simultaneously.

In this kind of situation, users share the system simultaneously. One example is when the other person in your group has all the files in his laptop and in order to work with your programs faster, you remote your laptop with his. This will allow you to view his desktop and all the files within his system. You could also manage to change his files since you are also working with his system. This kind of situation may lead to various security problems most especially on your personal files and of the things that you are currently working upon.

While a dedicated machine is a computer that services one primary function or task. For example is a computing device that has a built-in computer that is solely dedicated to compute numbers. Dedicated and time-share machine differs with each other when it comes to capabilities same as it would never have the same degree of security.

Case Study 2

Would a newspaper reporter and a supermarket manager use a handheld computer in their work?

A hand held computer is a mobile device and is a pocket-sized computing device, typically having a display screen with touch input and/or a miniature keyboard. 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 handheld computer greatly reduces data entry time by providing a way to record data quickly and easily. Data can then be transferred to a desktop or laptop computer database or spreadsheet application for manipulation and storage. Their small size and long battery life allow them to be used in situations where laptop computers are inconvenient.

Handheld devices have become ruggedized for use in mobile field management situations to record information in the field. They are used to achieve a variety of tasks for increasing efficiency that include digitizing notes, sending and receiving invoices, asset management , recording signatures, managing parts and scanning barcodes. Handheld computers used at work have molded over time into a variety of form factors, including smart phones on the low end, handheld PDAs, Ultra-Mobile PCs and Tablet PCs. Laptops do not come under handheld computers as they are not small enough to hold in one's hand.

Now, what does a newspaper reporter do?

A newspaper reporter investigates a subject, performs research and conducts interviews to gather information, then writes a newspaper article on what he or she discovered. Sometimes used synonymously with the word journalist, a newspaper reporter is usually someone who actually performs research and investigation into a subject or story and reports it.

As a newspaper reporter, you must be accurate, quick and provides proper data for the reader. In gathering information, you must interview someone for that information. Sometimes if the person you’ve interviewed speaks faster, you must have a proper gadget for that. The handheld computer greatly reduces data entry time by providing a way to record data quickly and easily. The data you then gathered would be transferred to a laptop or PC for encoding it and make it as an article.

One example of handheld computer is the new iPhone 4 that has all the features any journalist (CJ or PJ) needs to never again be in a newsroom.

Of these features include FaceTime, the ability for video calling (right now just WiFi capable) is a feat that will put an end to mobile video cameras such as the FlipCam, which could not even transmit data remotely.

Another is the overall video capabilities of the phone itself. No more is there a need for a film crew or bulky cameras for on-the-spot news. Point, shoot, edit, send. This is possible and will be the future. High school and college students will use this technology to enhance their newspapers’ websites as schools cut back on their budgets. Professional journalists and bloggers will do the same.

How about a delivery person for a courier service?

A courier is a person or company who delivers messages, packages and mail. Couriers are distinguished from ordinary mail services by features such as speed, security, tracking, signature, specialization and individualization of services, and committed delivery times, which are optional for most everyday mail services.

It has being proven and tested that some companies nowadays are using the latest technology for that faster and easier processing of their job. On of which is the DX group, a courier firm which handles a million items of mail daily, is rolling out handheld devices to its 850 couriers to ensure accurate delivery and create real-time parcel tracking. The system plans a route and delivery order for couriers, taking into account the time of day, likely amount of traffic, and number of deliveries in the area. It also monitors couriers’ locations, and warns customers and couriers of deliveries that are likely to be late.