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Friday, August 12, 2011

Quiz #9

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.

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, do not start a computer with removable media in the drives or ports. Never open an e-mail attachment unless you are expecting the attachment and it is from a trusted source. Disable macros in documents that are not from a trusted source. Install an antivirus program and a personal firewall. Stay informed about any new virus alert or virus hoax. 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 explain 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.

9. Identify risks and safeguards associated with wireless communications.  
- Wireless access poses additional security risks. Intruders connect to other wireless networks to gain free Internet access or an organization's confidential data. Some individuals intercept and monitor communications as they transmit. Others connect to a network through an unsecured wireless access point (WAP), sometimes using the techniques of war driving or war flying. Some safeguards include firewalls, reconfiguring the WAP, and ensuring equipment uses a wireless security standard, such as Wi-Fi Protected Access (WPA) and 802.11i.

10. Discuss ways to prevent health-related disorders and injuries due to computer use.  
- A computer-related repetitive strain injury (RSI) can include tendonitis and carpal tunnel syndrome (CTS). Another health-related condition is eyestrain associated with computer vision syndrome (CVS). To prevent health-related disorders, take frequent breaks, use precautionary exercises and techniques, and use ergonomics when planning the workplace. Computer addiction occurs when the computer consumes someone's entire social life.

11. Recognize issues related to information accuracy, intellectual property rights, codes of conduct, and green computing. 
- Computer ethics govern the use of computers and information systems. Issues in computer ethics include the responsibility for information accuracy and the intellectual property rights to which creators are entitled for their works. An IT (information technology) code of conduct helps determine whether a specific computer action is ethical or unethical. Green computing reduces the electricity and environmental waste while using a computer.

12. Discuss issues surrounding information privacy, including electronic profiles, cookies, spyware and adware, spam, phishing, privacy laws, social engineering, employee monitoring, and content filtering. 
- Information privacy is the right of individuals and companies to deny or restrict the collection and use of information about them. Issues surrounding information privacy include the following. An electronic profile combines data about an individual's Web use with data from public sources, which then is sold. A cookie is a file that a Web server stores on a computer to collect data about the user. Spyware is a program placed on a computer that secretly collects information about the user. Adware is a program that displays an online advertisement in a banner or pop-up window. Spam is an unsolicited e-mail message or newsgroup posting sent to many recipients or newsgroups at once. Phishing is a scam in which a perpetrator attempts to obtain personal or financial information. The concern about privacy has led to the enactment of many federal and state laws regarding the disclosure of data. As related to the use of computers, social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of the trusting human nature of some victims and the naivety of others. Employee monitoring uses computers to observe, record, and review an employee's computer use. Content filtering restricts access to certain materials on the Web.

 
 
       
 

Monday, August 1, 2011

Quiz #8

1. Define the term, database, and explain how a database interacts with data and information.
Database collection of data organized in a manner that allows access, retrieval, and use of that data.


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
- Characters numbers, letters, space, punctuation marks, or other symbols
- Field is a combination of one or more related characters
- 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 the database and each field in those files
-File Retrieval and Maintenance 
-Data Security 
-Back up and Recovery


5. Differentiate between a file processing approach and the database approach.
-   In a file processing system, each department or area within an organization has its own set of data files. The records in one file may not relate to the records in any other file. Two major weaknesses of file processing systems are redundant data (duplicated data) and isolated data. With a 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 than file processing systems. Data in a database also can be more vulnerable than data in file processing systems.

6. Describe characteristics of relational, object-oriented, and multidimensional databases.
-    A data model consists of rules and standards that define how the database organizes data. Three popular data models are relational, object-oriented, and multidimensional. A relational database stores data in tables that consist of rows and columns. A relational database developer refers to a file as a relation, a record as a tuple, and a field as an attribute. A relational database user refers to a file as a table, a record as a row, and a field as a column. A relationship is a link within the data in a relational database. Structured Query Language (SQL) allows users to manage, update, and retrieve data in a relational database. An object-oriented database (OODB) stores data in objects. An object is an item that contains data, as well as the actions that read or process the data. Applications appropriate for an object-oriented database include a multimedia database, a groupware database, a computer-aided design (CAD) database, a hypertext database, and a hypermedia database. Object-oriented databases often use an object query language (OQL) to manipulate and retrieve data. A multidimensional database stores data in dimensions. These multiple dimensions, sometimes known as a hypercube, allow users to access and analyze any view of the database data. No standard query language exists for multidimensional databases. One application that uses multi dimensional databases is a data warehouse, which is a huge database that stores and manages the data required to analyze historical and current transactions. A smaller version of a data warehouse is the data mart, which contains a database that helps a specific group or department make decisions.

7.Explain how to access Web databases.
-   To access data in a Web database, you fill in a form or enter search text on a Web page, which is the front end to the database. A Web database usually resides on a database server, which is a computer that stores and provides access to a database. One type of program that manages the sending and receiving of data between the front end and the database server is a CGI (Common Gateway Interface) script.

8. 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. 
-


9.  Identify database design guidelines and discuss the responsibilities of database analysts and administrators.
- A database analyst (DA), or data modeler, focuses on the meaning and usage of data. The DA decides on the placement of fields, defines data relationships, and identifies users' access privileges. A database administrator (DBA) requires a more technical inside view of the data. The DBA creates and maintains the data dictionary, manages database security, monitors database performance, and checks backup and recovery procedures. In small companies, one person often is both the DA and DBA. In larger companies, the responsibilities of the DA and DBA are split among two or more people.

10. Discuss techniques to prevent unauthorized computer access and use
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Sunday, July 31, 2011

Sunday, July 24, 2011

Quiz #7

1. Discuss the components required for successful communications.
Successful communications requires a sending device that initiates a transmission instruction, a communications device that connects the sending device to a communications channel, a communications channel on which the data travels, a communications device that connects the communications channel to a receiving device, and a receiving device that accepts the transmission of 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.
All types of computers and mobile devices serve as sending and receiving devices in a communications system. This includes mainframe computers, servers, desktop computers, notebook computers, Tablet PCs, smart phones, portable media players, and GPS receivers.

3. Describe uses of computer communications.
Communications technologies include the Internet, Web, e-mail, instant messaging, chat rooms, newsgroups, blogs, wikis, RSS, VoIP, FTP, Web folders, video conferencing, and fax machine or computer fax/modem.


4. List advantages of using a network.
  • Speed
  • Cost
  • Security
  • Centralized Software Management
  • Resource Sharing
  • E-mail
  • Work group computing 
5. Differentiate among client/server, peer-to-peer, and P2P networks.
A client server setup has servers, which are dedicated machines that perform specific functions in the network. A server can be used to manage a network's email (mail server), database (database server), files (file server), printers (print server), or access an anti-virus (security server). This division of labor between components make a client server setup more efficient than a peer-to-peer network.
- A peer-to-peer network setup Simple network that connects fewer than 10 computers. Each computer, or peer, has equal capabilities. 
P2P is an Internet peer-to-peer network Enables users to connect to each other’s hard disks and exchange files directly.

6. Describe the various network communications standards.
- Ethernet technology allows computers to contend for access to network  
-Token Ring technology controls access to network by requiring devices to pass a special signal called token.
-TCP/IP (Transmission Control Protocol/Internet Protocol) technology transmits data by breaking it up into small pieces, or packets
-802.11 (WiFi) is family of standards for wireless LANs
-Bluetooth Short-range radio waves transmit data between Bluetooth devices
-UWB specification allows data to be transferred wirelessly via short-range radio waves
-IrDA specification allows data to be transferred wirelessly via infrared light waves
-WiMax/802.16 standard that specifies how wireless devices communicate over the air in a wide area
-RFID    uses radio signals to communicate with a tag placed in an object 
-WAP allow wireless mobile devices to access Internet


7. Explain the purpose of communications software.
-Programs that help users establish connection to Internet, other network, or another computer 
-Programs that help users manage transmission of data, instructions, and information

-Programs that provide an interface for users to communicate with one another


  
8. Describe various types of lines for communications over the telephone network.
- PSTN Worldwide telephone system that handles voice-oriented telephone calls
-Dial Up Line Temporary connection using telephone line for communications 
-Dedicated Line Always-on connection between two communications devices


9. Describe commonly used communications devices.
- Dial Up Modems A dial-up modem converts digital signals to analog signals and vice versa

-ISDN/DSL Modems Usually external devices in which one end connects to a telephone line and the other    end connects to a port on the system unit 

-Cable Modem Sends and receives data over cable television network.Broadband modem.        
-Wireless Modem Allows access to the Web wirelessly from a notebook computer, a PDA, a smart phone, or other mobile device.

-Network Card Ã˜

Adapter card, PC Card, ExpressCard module, USB network adapter, or flash card that enables computer or device to access network .
,
-Wireless Access  Point 

Central communications device that allows computers and devices to transfer data wirelessly among themselves or wirelessly to a wired network .
-Router Connects computers and transmits data to correct destination on network.
 
-Hub or Switch Device that provides central point for cables in network.
 





             




  




  



 








Quiz #6

1. Define system software and identify the two types of system software.
 System software refers to the files and programs that make up your computer's operating system. System files include libraries of functions, system services, drivers for printers and other hardware, system preferences, and other configuration files. The programs that are part of the system software include assemblers, compilers, file management tools, system utilities, and debuggersThe system software is installed on your computer when you install your operating system. You can update the software by running programs such as "Windows Update" for Windows or "Software Update" for Mac OS X. 
       2 Types Of System Software
  • Operating System
  • Utility Program
2. Briefly describe various server operating systems: Windows Server, UNIX,Linux, Solaris, and NetWare.

Windows Server is a brand name for a group of server operating systems released by Microsoft Corporation
- Unix  is amultitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie,Brian Kernighan, Douglas McIlroy, and Joe Ossanna. The Unix operating system was first developed in assembly language, but by 1973 had been almost entirely recoded inC, greatly facilitating its further development and porting to other hardware. 
- Linux  Linux can be installed on a wide variety of computer hardware, ranging from mobile phones, tablet computers, routers and video game consoles, todesktop computers, mainframes and supercomputers. Linux is a leading serveroperating system, and runs the 10 fastest supercomputers in the world. The development of Linux is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU General Public License
- Solaris  Solaris is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS and Time Slider. Solaris supports SPARC-based and x86-based workstations and servers from Sun and other vendors, with efforts underway to port to additional platforms. 
- NetWare It initially usedcooperative multitasking to run various services on a personal computer, with network protocols based on the archetypal Xerox Network Systems stack.

3. Summarize the features of several embedded operating systems: Windows Embedded CE, Windows Mobile, Palm OS, iPhone OS, BlackBerry, Google Android, Embedded Linux, and Symbian OS.
Microsoft Windows CE  is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows. Windows CE is optimized for devices that have minimal storage—a Windows CE kernel may run in under a megabyte of memory
- Features Windows Mobile
Palm OS  is designed for ease of use with a touchscreen-based graphical user interface.
Features:

  • Simple, single-tasking environment to allow launching of full screen applications with a basic, common GUI set
  • Monochrome or color screens with resolutions up to 480x320 pixel
  • Handwriting recognition input system called Graffiti 2
  • HotSync technology for data synchronization with desktop computers
  • Sound playback and record capabilities
  • Simple security model: Device can be locked by password, arbitrary application records can be made private
  • TCP/IP network access
  • Serial port/USBinfraredBluetooth and Wi-Fi connections
  • Expansion memory card support
  • Defined standard data format for personal information management applications to store calendar, address, task and note entries, accessible by third-party applications.
- iPhone OS Features:
  • Multitasking
  • Fast App Switching
  • Local Notification
  • App Folders
  • New App E-mail
  • iBooks
- Blackberry Features:

  • Multi-touch Interface
  • Webkit Browser
  • Home Screen
  • Universal Search
  • Context Sensitive Menus
  • Social Tools
Google Android Features:
  • Handset layouts
  • Storage
  • Connectivity
  • Messaging
  • Multiple language support
  • Web browser
  • Java support
  • Media support
  • Streaming media support
  • Additional hardware support
  • Multi-touch
  • Bluetooth
  • Video calling
  • Multitasking
  • Tethering
  • Screen Capture
4. Explain the purpose of several utility programs: file manager, search utility, image viewer, uninstaller, disk cleanup, disk defragmenter, backup and restore utilities, screen saver,
 personal firewall, antivirus programs, spyware and adware removers, Internet filters, file compression, media player, disc burning, and personal computer maintenance.
  • File Manager - is a computer program that provides a user interface to work with file systems. The most common operations performed on files or groups of files are: create, open, edit, viewprintplay, rename, move, copydelete, search/find, and modify attributes, properties and permissions.
  • Image Vieweris a computer program that can display stored graphical image
  • Uninstalleralso called a deinstaller, is a utility software designed to remove other software or parts of it from a computer. 
  • Disk cleanupis a computer maintenance utility included in Microsoft Windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files. 
  • Disk defragmenteris a process that reduces the amount of fragmentation in file systems
  • Backup Utility - allows users to copy files to another storage medium.
  • Restore Utility - reverses the process and returns backed up files to their original form
  • Screen Saver - causes a display device’s screen to show a moving image or blank screen if no activity occurs for a specified time
  • Personal Firewall - detects and protects a personal computer from unauthorized intrusions
  • Anti Virus Program - protects a computer against viruses
  • Spyware removers - detects and deletes spyware and other similar programs
  • Adware remover-  is a program that detects and deletes adware
  • Internet Filtersare programs that remove or block certain items from being displayed
  • File Compression - shrinks the size of a file(s), compressing files frees up room on the storage media.
  • Media Playerallows you to view images and animation, listen to audio, and watch video files on your computer
  • Disc Burning - writes text, graphics, audio, and video files on a recordable or rewritable optical disc.
  • Personal Computer Maintenance - identifies and fixes operating system problems, detects and repairs disk problems, and includes the capability of improving a computer’s performance