tnx sa blogger, nkit-an na jud naq ang work ni maria....tnx maria

My Answers - Comped321 Quiz 9 (August 8, 2011)

1. Define the term, computer security risks, and briefly describe the types
of cybercrime perpetrators: hacker, cracker, script kiddie, corporate spy,
unethical employee, cyberextortionist, and cyberterrorist. 

Computer security is a branch of computer technology known as Information Security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users. 

Cybercrime Perpetrators

Hacker refers to a computer programmer who is able to create usable computer programs where none previously existed. 

Cracker is a variation of hacker, with the analogy equal to a safe cracker. Some individuals use the term cracker in an attempt to differentiate from the honorable computer programmer definition of hacker.

Script kiddy is an individual who executes computer scripts and programs written by others. Their motive is to hack a computer by using someone else’s software. Examples include password decryption programs and automated access utilities. 

Corporate Spy - have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information.

Unethical employee - break into their employers' computer for a variety of reasons. Some simply want to exploit security weakness.

Cyberextortionist - is someone who uses e-mail as a vehicle for extortion. These perpetrator s send an organization a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launch an attack that will compromise the organization s network - if they are not paid of a sum of money.

Cyber-terrorist - a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism

2. Describe various types of Internet and network attacks (computer viruses,
worms, Trojan horses, rootkits, botnets, denial of service attacks, back
doors, and spoofing), and identify ways to safeguard against these attacks,
including firewalls, intrusion detection software, and honeypots. 

A computer virus is a potentially damaging program that affects, or infects, a computer negatively by altering the way the computer works without the user's knowledge or permission. 
A worm is a program that copies itself repeatedly, using up resources and possibly shutting down the computer or network.
A Trojan horse is a program that hides within or looks like a legitimate program. 
A root kit is a program that hides in a computer and allows someone from a remote location to take full control of the computer. 
To take precautions against this malware,
1.Do not start a computer with removable media in the drives or ports. 
2. Never open an e-mail attachment unless you are expecting the attachment and it is from a trusted source.
3. Disable macros in documents that are not from a trusted source. 
4. Install an antivirus program and a personal firewall. 
5. Stay informed about any new virus alert or virus hoax. 
6. To defend against a botnet, a denial of service attack, improper use of a back door, and spoofing, users can install a firewall, install intrusion detection software, and set up a honeypot.


3. Discuss techniques to prevent unauthorized computer access and use

Unauthorized access is the use of a computer or network without permission. Unauthorized use is the use of a computer or its data for unapproved or illegal activities. Organizations can take measures such as implementing a written acceptable use policy (AUP), a firewall, intrusion detection software, an access control, and an audit trail. Access controls include a user name and password or passphrase, a CAPTCHA, a possessed object, and a biometric device.

4. Identify safeguards against hardware theft and vandalism

Hardware theft is the act of stealing computer equipment. Hardware vandalism is the act of defacing or destroying computer equipment. The best preventive measures against hardware theft and vandalism are common sense and a constant awareness of the risk. Physical devices and practical security measures, such as locked doors and windows, can help protect equipment. Passwords, possessed objects, and biometrics can reduce the risk of theft or render a computer useless if it is stolen.

5. Explain the ways software manufacturers protect against software piracy.

Software piracy is the unauthorized and illegal duplication of copyrighted software. To protect themselves from software piracy, manufacturers issue a license agreement and require product activation.

6. Discuss how encryption works, and explains why it is necessary

Encryption prevents information theft and unauthorized access by converting readable data into unreadable characters. To read the data, a recipient must decrypt, or decipher, it into a readable form. An encryption algorithm, or cypher, converts readable plaintext into unreadable cipher text. Encryption is used to protect information on the Internet and networks.

7. Discuss the types of devices available that protect computers from
system failure

A system failure is the prolonged malfunction of a computer. A common cause of system failure is an electrical power variation such as noise, an undervoltage, or an overvoltage. A surge protector, also called a surge suppressor, uses special electrical components to smooth out minor noise, provide a stable current flow, and keep an overvoltage from reaching the computer and other electronic equipment. An uninterruptible power supply (UPS) contains surge protection circuits and one or more batteries that can provide power during a temporary loss of power.

8. Explain the options available for backing up computer resources.

A backup is a duplicate of a file, program, or disk that can be used to restore the file if the original is lost, damaged, or destroyed. Users can opt for a full backup or a selective backup. Some users implement a three-generation backup policy that preserves three copies of important files: the grandparent, the parent, and the child. Others use RAID or continuous backup. Most operating systems and backup devices include a backup program.

My Answers - Comped321 Quiz 8 (August 1, 2011)

1. Define the term, database, and explain how a database interacts with data
and information.

A database is an organized collection of data for one or more purposes, usually in digital form.

Data is collection of unprocessed items text, numbers, images, video and audio.
Information is a processed data, organized, meaningful and useful.

2. Describe file maintenance techniques (adding records, modifying records, deleting records) and validation techniques.
- File Maintenance refers to the procedures that keep data current.
- Adding Records users add new records to a file when they obtain new data Disc
- Modifying Records users modify a record to correct inaccurate data or update old data
- Deleting Records When a record no longer is needed, a user deletes it from a file
- Validation Techniques compares data with a set of rules or values to find out if the data is correct  

·                     Alphabetic/Numeric check

·                     Range check

·                     Consistency check

·                     Completeness check

·                     Check digit

·                     Other checks

3. Discuss the terms character, field, record, and file

Field is a combination of one or more characters. It is the smallest unit of data user accesses

Record is a group of related fields.

File is a collection of related records

4. Discuss the functions common to most database management systems:
data dictionary, file retrieval and maintenance, data security, and backup
and recovery.

Data dictionary contains data about each file in a database and each field within the files.

Backup is the copy of the database. A log is a listing of activities that change the contents of the database. 

Recovery Utility uses the logs and/or backups to restore the database.

5. Differentiate between a file processing approach and the database
approach.

File processing approach each department or area within organization has its own set of files.

Database approach- many programs and users share the data in a database. The database approach reduces data redundancy, improves data integrity, shares data, permits easier access, and reduces development time. A database, however, can be more complex than a file processing system, requiring special training and more computer memory, storage, and processing power. Data in a database also can be more vulnerable than data in file processing system.

6. Describe characteristics of relational, object-oriented, and
multidimensional databases.
    An object-oriented database (OODB) stores data in objects
•Object-oriented databases often use Object Query Language (OQL) to manipulate and retrieve data.
    A relational database stores data in tables that consist of rows and columns
        –Each row has a primary key
        –Each column has a unique name
        •A relationship is a link
    A multidimensional database can store data in more than two dimensions of data
        –Can consolidate data much faster than a relational database

7. Explain how to access Web databases.

Web database  database you can access through web by filing in a form in a web page.
A Web database links to a form on a Web page. To access data in a Web database, you fill on the form or enter search text on a Web page. A Web database usually resides on a database server, which is a computer that store and provides access to a database.
 
8. Define the term, computer security risks, and briefly describe the types
of cyber crime perpetrators: hacker, cracker, script kiddie, corporate spy,
unethical employee, cyber extortionist, and cyber terrorist.

Computer security is a branch of computer technology known as Information Security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users. 

Cyber crime Perpetrators

Hacker refers to a computer programmer who is able to create usable computer programs where none previously existed. 

Cracker is a variation of hacker , with the analogy equal to a safe cracker. Some individuals use the term cracker in an attempt to differentiate from the honorable computer programmer definition of hacker.

Script kiddy is an individual who executes computer scripts and programs written by others. Their motive is to hack a computer by using someone else’s software. Examples include password decryption programs and automated access utilities.

Corporate Spy - have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information.

Unethical employee - break into their employers' computer for a variety of reasons. Some simply want to exploit security weakness.

Cyber extortionist - is someone who uses e-mail as a vehicle for extortion. This perpetrator is send an organization a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launches an attack that will compromise the organization s network - if they are not paid of a sum of money.

Cyber-terrorist - a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism

9. Identify database design guidelines and discuss the responsibilities of
database analysts and administrators.

10. Discuss techniques to prevent unauthorized computer access and use

Operating system and software patches and updates

There is no such thing as perfect software, often a software program may have several issues and could potentially have security vulnerabilities that can leave your computer open to attacks that compromise your computer and your data.

Software patches, updates, and drivers are made available, often for free, to consumers to help keep a software program and operating systems running properly and secure. If the program you're using does not have any method of checking for updates on its own it is up to you to verify the program is up-to-date. Often this can be done by visiting the web site of the developer who created the program. A listing of third-party companies and links to each of their pages can be found on our third-party support page.

·                     How to update a Microsoft Windows computer.

Passwords

Make sure a password has been set on computer. Default passwords such as password, root, admin or no password will allow easy access to your computer or your Internet account.

1.                   Change passwords often. It is recommended at least once every few months.

2.                   Create a BIOS password.

3.                   When creating a password, add numbers or other characters to the password to make it more difficult to guess; for example: 1mypassword23!.

4.                   Do not use sticky notes around your computer to write down passwords. Instead use a password manager.

·                     Complete information and links to information about computer passwords.

Get a hardware or software firewall

We highly recommend all computer users have a firewall solution. There are two ways a firewall can protect your computer and network.

1.                   Hardware firewall - A hardware firewall is a hardware device that is connected to your network. Often many home users who have a home network use their network router as a firewall solution.

2.                   Software firewall - A software firewall is a software program that you install on your computer that helps protect that computer from unauthorized incoming and outgoing data. Below is a listing of a few of the more widely used software firewall programs.

Agnitum Outpost Firewall
BlackICE PC Protection
Kerio Personal Firewall
Sygate Firewall
Tiny software Tiny Personal Firewall
Network Associates
Zone Labs Zone Alarm

Note: A software firewall is only going to protect the computer that has the firewall installed on it.

In addition to the above listed firewall software programs many of the antivirus scanners released today also include their own version of a firewall program. If you have an antivirus scanner that also has a firewall program you do not need to worry about getting one of the above programs or another third-party firewall program.

·                     How to enable or disable the Microsoft Windows firewall.

Trojans, viruses, spyware, and other malware

Software Trojans, viruses, spyware, and other malware can not only damage or destroy your computer data Internet or even log all your keystrokes to capture sensitive data such as passwords and credit card information. but is also capable of monitoring your computer to learn more about your viewing habits on the

To help protect your computer from these threats we suggest installing a virus protection program as well as a spyware protection program.

·                     What are the current available antivirus programs?

·                     My web browser has been hijacked.

Know how to handle e-mails

Today, e-mail is one of the most popular features on the Internet. Being able to identify threats sent through e-mail can help keep your computer and your personal information safe. Below are some of the most common threats you may encounter while using e-mail.

·                     Attachments - Never open or run e-mail attachments. Viruses, spyware, and other malware are commonly distributed through e-mails that have attachments. For example, an e-mail may want you to open an attachment of a funny video, when it's actually a virus.

·                     Phishing - Phishing or an e-mail phish is an e-mail that appears to be from an official company (such as your bank) indicating you need to log onto the site to check your account settings. However, the e-mails are actually sites setup to steal confidential information such as your passwords, credit card information, social security information, etc. See the phishing definition for additional information about this term as well as examples of these e-mails.

Alternative browser

Before the release of Microsoft Windows XP SP2 and Internet Explorer 7.0, Microsoft Internet Explorer was notorious for security and spyware related issues. Although it has improved since then we still highly recommend considering an alternative browser such as Mozilla Firefox.

Run system scans to check for vulnerabilities

There are several sites on the Internet that allow users to check their computers for potential threats or issue their network or computer may have that can allow users unauthorized access to their computer. Below is a listing of recommend sites to try: 

Gibson Research Corporation - The Gibson Research Corporation, or GRC, is a great location to learn about network security as well as well as test your computer or network for vulnerabilities. 

Hacker Wacker - Another great site with computer security related information, help, and programs to help test your computer and network.

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My Answers - Comped321 Quiz 7 (July 21, 2011)

1. Discuss the components required for successful communications.

Computer communications describes a process in which one computer transfers data, instructions and information to another computer or computers. Successful communications require a sending device that initiates an instruction to transmit data, instructions or information, a communications device that converts or formats the data, instructions or information from the sending device into signals carried by a communications channel, and a communications channel or path on which the signals travel. Also required are a communications device that receives signals from the communications channel and converts or formats them so the receiving device can understand the signals, and a receiving device that accepts the data, instructions or information.

2. Identify various sending and receiving devices.

A sending device initiates the transmission of data, instructions, and information while a receiving device accepts the items transmitted.

Microcomputers, minicomputers, and mainframes all can serve as sending and receiving devices.

Besides, Internet appliances and Web enabled handheld computers and devices (e.g. cellular telephones and pagers) can also serve sending and receiving devices.

3. Describe uses of computer communications.

Today most computers are capable (through either a phone line or a cable connection) of exchanging information over the Internet. Your child can send a message from his or her computer to the computer of a neighbor or a friend on the other side of the planet. Students might use computers to communicate with their classmates about homework assignments, group projects, or other school-related activities. They may also use them to submit homework assignments and presentations to their teachers.

4. List advantages of using a network.

By using a network, people can communicate efficiently and easily via email, instant messaging, chat rooms, telephony, videophone calls and videoconferencing. In a networked environment, each computer on the network can access and use hardware on the network, such as printers or scanners. Authorised computers on a network can also access data and information stored on other computers in the network. Users connected to a network can access software (programs) on the network.

5. Differentiate among client/server, peer-to-peer, and P2P networks.

Network architecture is the logical design of the components of a network, including the number and type of servers, workstations and network resources.

A peer-to-peer LAN is a simple, inexpensive network that typically connects less than 10 computers together. Each computer on a peer-to-peer network can share hardware (such as a printer), data or information located on any other computer in the network.

A client/server LAN is a network in which one or more computers acts as a server and the other computers on the network can request services from the server.

6. Describe the various network communications standards.

Network standards define:

•  Way devices access the medium
•  Speed on different types of networks
•  Types of network technology (cable / wireless)

Protocols

•  Rules on how devices communicate with each other
•  Data format used
•  Coding Scheme
•  Error Handling
•  Sequencing techniques etc.
•  Hardware / Software Vendors try to meet these guidelines

ANSI, IEEE

Standardizing Organization

7. Explain the purpose of communications software.

The purpose of communication software is used to provide remote access to systems and is also    used to exchange messages in text, audio and video format for the purpose of communication. This software sends and receives data over telephone lines through modems. The communication software allows computers in different geographical regions to communicate with each other through terminal emulators, file transfer programs, chat and instant messaging programs.

8. Describe various types of lines for communications over the telephone network.

A telephone network is a telecommunications network used for telephone calls between two or more parties.

There are a number of different types of telephone network:

• A fixed line network where the telephones must be directly wired into a single telephone exchange. This is known as the public switched telephone network or PSTN.
• A wireless network where the telephones are mobile and can move around anywhere within the coverage area.
• A private network where a closed group of telephones are connected primarily to each other and use a gateway to reach the outside world. This is usually used inside companies and call centres and is called a private branch exchange (PBX).

9. Describe commonly used communications devices.

Dial-up modem

• A dial-up modem converts digital signals to analog signals and vice versa
• Usually in the form of an adapter card

DSL Modem / ISDN Modem-Cable Modem

• Send and receive digital data from DSL(Digital Subscriber Line) / ISDN

Cable Modem

•  Sends and receives data over cable television (CATV) network
•  Much faster than dial-up modem or ISDN
•  Sometimes called a broadband modem

Wireless Modem 

• Allows access to the Web wirelessly from a notebook computer, a smart phone, or other mobile device. 

Hub or Switch 

• Device that provides central point for cables in network. 

Router

• Connects computers and transmits data to correct destination on network. 

10. Discuss different ways to set up a home network.

Setting up a home network

Before you start: To decide what type of network to set up or to find out what hardware and cables you need, see What you need to set up a home network. That topic has information about the different types of networks (also known as network technologies), as well as hardware requirements for each type.

Once you know what type of network you want and have the necessary hardware, there are four possible steps to take (two of these are not always required):

1.       Install any necessary hardware.

2.       Set up an Internet connection (optional).

3.       Connect the computers.

4.       Run the Set Up a Wireless Router or Access Point wizard (wireless only).

Each of these steps is described in detail later in this article.

Start by setting up one computer. Once you set up the network and you are sure that the first computer is working correctly, you can add additional computers or devices.

Install the hardware

Install network adapters in any computers that need them. (Follow the installation instructions in the information that came with each adapter.)

Set up or verify an Internet connection (optional)

You don't need an Internet connection to set up a network, although most people want to use their network to share an Internet connection. To set up an Internet connection, you need a cable or DSL modem and an account with an Internet service provider (ISP). Then open the Connect to the Internet wizard and follow the instructions.

Connect the computers

Turn on all computers or devices, such as printers, that you want to be part of your network. If your network is wired Ethernet or HPNA, it should be set up and ready to use. You should test your network (see below) to make sure that all computers and devices are connected correctly.

Run the Set Up a Wireless Router or Access Point wizard

If your network is wireless, run the Set up a Wireless Router or Access Point wizard on the computer attached to the router.

·         Open Set Up a Wireless Router or Access Point by clicking the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center. In the left pane, click Set up a connection or network, and then click Set up a wireless router or access point.

The wizard will walk you through the process of adding other computers and devices to the network. For more information, see Add a device or computer to a network.

Test your network

It's a good idea to test your network to make sure that all of the computers and devices are connected and working properly. To test your network, do the following on each network computer: Click the Start button, and then click Network.

Changing TCP/IP settings

If you need to adjust TCP/IP settings for your network, see Change TCP/IP settings.

Connecting your mobile PC from work to your home network

To connect the mobile PC that you use at work to the Internet or to your work network from your home network, you must have a network connection set up at home. For information about using your mobile PC on your home network, see Switching between your home and workplace networks.

11. Identify various physical and wireless transmission media.