Introduction To Security
Your home computer is a popular target for intruders. Why? Because intruders want what you’ve stored there. They look for credit card numbers, bank account information, and anything else they can find. By stealing that information, intruders can use your money to buy themselves goods and services.
But it’s not just money-related information they’re after. Intruders also want your computer’s resources, meaning your hard disk space, your fast processor, and your Internet connection. They use these resources to attack other computers on the Internet. In fact, the more computers an intruder uses, the harder it is for law enforcement to figure out where the attack is really coming from. If intruders can’t be found, they can’t be stopped, and they can’t be prosecuted.
Why are intruders paying attention to home computers? Home computers are typically not very secure and are easy to break into. When combined with high-speed Internet connections that are always turned on, intruders can quickly find and then attack home computers. While intruders also attack home computers connected to the Internet through dial-in connections, high-speed connections (cable modems and DSL modems) are a favorite target.
No matter how a home computer is connected to the Internet, intruders’ attacks are often successful. Many home computer owners don’t realize that they need to pay attention to computer security. In the same way that you are responsible for having insurance when you drive a car, you need to also be responsible for your home computer’s security. This document explains how some parts of the Internet work and then describes tasks you can do to improve the security of your home computer system. The goal is to keep intruders and their programs off your computer.
How do intruders break into your computer? In some cases, they send you email with a virus. Reading that email activates the virus, creating an opening that intruders use to enter or access your computer. In other cases, they take advantage of a flaw or weakness in one of your computer’s programs – a vulnerability – to gain access.
Once they’re on your computer, they often install new programs that let them continue to use your computer – even after you plug the holes they used to get onto your computer in the first place. These backdoors are usually cleverly disguised so that they blend in with the other programs running on your computer.
The next section discusses concepts you need to know, especially trust. The main part of this document explains the specific issues that need your attention. There are examples of how to do some of these tasks to secure a Microsoft Windows 2000-based computer. We also provide checklists you can use to record information about the steps you have taken to secure your computer. Finally, a glossary defines many of the technical terms used in this document. Unless otherwise stated in the glossary, the definitions come from the Webopedia Online Dictionary for Computer and Internet Terms
Whether your computer runs Microsoft® Windows®, Apple’s Mac OS, LINUX, or something else, the issues are the same and will remain so as new versions of your system are released. The key is to understand the security-related problems that you need to think about and solve.
Your home computer is a popular target for intruders. Why? Because intruders want what you’ve stored there. They look for credit card numbers, bank account information, and anything else they can find. By stealing that information, intruders can use your money to buy themselves goods and services.
But it’s not just money-related information they’re after. Intruders also want your computer’s resources, meaning your hard disk space, your fast processor, and your Internet connection. They use these resources to attack other computers on the Internet. In fact, the more computers an intruder uses, the harder it is for law enforcement to figure out where the attack is really coming from. If intruders can’t be found, they can’t be stopped, and they can’t be prosecuted.
Why are intruders paying attention to home computers? Home computers are typically not very secure and are easy to break into. When combined with high-speed Internet connections that are always turned on, intruders can quickly find and then attack home computers. While intruders also attack home computers connected to the Internet through dial-in connections, high-speed connections (cable modems and DSL modems) are a favorite target.
No matter how a home computer is connected to the Internet, intruders’ attacks are often successful. Many home computer owners don’t realize that they need to pay attention to computer security. In the same way that you are responsible for having insurance when you drive a car, you need to also be responsible for your home computer’s security. This document explains how some parts of the Internet work and then describes tasks you can do to improve the security of your home computer system. The goal is to keep intruders and their programs off your computer.
How do intruders break into your computer? In some cases, they send you email with a virus. Reading that email activates the virus, creating an opening that intruders use to enter or access your computer. In other cases, they take advantage of a flaw or weakness in one of your computer’s programs – a vulnerability – to gain access.
Once they’re on your computer, they often install new programs that let them continue to use your computer – even after you plug the holes they used to get onto your computer in the first place. These backdoors are usually cleverly disguised so that they blend in with the other programs running on your computer.
The next section discusses concepts you need to know, especially trust. The main part of this document explains the specific issues that need your attention. There are examples of how to do some of these tasks to secure a Microsoft Windows 2000-based computer. We also provide checklists you can use to record information about the steps you have taken to secure your computer. Finally, a glossary defines many of the technical terms used in this document. Unless otherwise stated in the glossary, the definitions come from the Webopedia Online Dictionary for Computer and Internet Terms
Whether your computer runs Microsoft® Windows®, Apple’s Mac OS, LINUX, or something else, the issues are the same and will remain so as new versions of your system are released. The key is to understand the security-related problems that you need to think about and solve.
Human beings are trusting by nature. We trust much of what we hear on the radio, see on television, and read in the newspaper. We trust the labels on packages. We trust the mail we receive. We trust our parents, our partner or spouse, and our children. We trust our co-workers. In fact, those who don’t trust much are thought to be cynical. Their opinions may be all too quickly ignored or dismissed.
Information in the Clear
When you have a conversation with someone in your living space, everybody within earshot can hear the words and probably understand them. If your conversation is especially loud and your windows open, even passersby can hear. If you want privacy, you and your conversation partner need to go to another room and close the doors and windows. Anyone, or, more accurately, any program, in that Internet room that can hear that conversation can also probably understand it. Why? Because just like the conversation at home, most Internet conversations are in the clear, meaning that the information exchanged between computer systems is not concealed or hidden in any way.
Again, this is how the Internet works. You need to know that the information sent across the Internet may be at risk of others listening in, capturing what you send, and using it for their own benefit.
Again, this is how the Internet works. You need to know that the information sent across the Internet may be at risk of others listening in, capturing what you send, and using it for their own benefit.
Install and Use a File Encryption Program and Access Controls
Let’s return to your living space and our original analogy. Think about your checkbook, your insurance policies, perhaps your birth certificate or passport, and other important documents you have at home. Where are they? They’re probably stored in a filing cabinet or a safe, either of which that can be or is routinely locked. Why do you store these important items in a locked container?
Without realizing it, you are satisfying one of the three components of information security – confidentiality. Confidentiality means keeping secrets secret. Only those who are supposed to see that information should have access to it. You are keeping information sensitive to you and others away from those who should not be able to get to it, for example a family member or an intruder. By the way, the other two components of information security are integrity (Has my information changed?) and availability (Can I get to my information whenever I need it?).
Without realizing it, you are satisfying one of the three components of information security – confidentiality. Confidentiality means keeping secrets secret. Only those who are supposed to see that information should have access to it. You are keeping information sensitive to you and others away from those who should not be able to get to it, for example a family member or an intruder. By the way, the other two components of information security are integrity (Has my information changed?) and availability (Can I get to my information whenever I need it?).
Whether paper files around your living space or files and folders on your computer, limit access where you can. On your computer, use encryption programs either when you can’t restrict access to the extent that you’d like or when you want even more security protecting your computer files and folders.

