Huwebes, Agosto 11, 2011

Quiz 9

1.
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. The term computer system security means the collective processes and mechanisms by which sensitive and valuable information and services are protected from publication, tampering or collapse by unauthorized activities or untrustworthy individuals and unplanned events respectively. The strategies and methodologies of computer security often differ from most other computer technologies because of its somewhat elusive objective of preventing unwanted computer behavior instead of enabling wanted computer behavior.



A hacker is a person who breaks into computers and computer networks for profit, in protest, or because they are motivated by the challenge. The subculture that has evolved around hackers is often referred to as the computer underground but it is now an open community.
Other definitions of the word hacker exist that are not related to computer security. They are subject to the long standing hacker definition controversy about the true meaning of hacker. In this controversy, the term hacker is reclaimed by computer programmers who argue that someone breaking into computers is better called a cracker, not making a difference between computer criminals ("black hats") and computer security experts ("white hats"). Some white hat hackers claim that they also deserve the title hacker, and that only black hats should be called crackers.
A script kiddie or skiddie occasionally skidscript bunny l script kitty script-running juvenile (SRJ) or similar, is a derogatory term used to describe those who use scripts or programs developed by others to attack computer systems and networks and deface websites.
2.
A computer virus affects the computer negatively by altering the way the computer works, Worm copies itself repeatedly, using up resources and possibly shutting down computer or network. Trojan horse is a malicious program that hides within or looks like a legitimate program and Rootkit is a program that hides in a computer and allows someone from a remote location to take full control. A denial service attack is an assualt which disrupts computer access to an Internet service such as the Web or-email. Back door is a program or set of instructions in a program that allow users to bypass security controls when accessing a computer resource while spoofing is a tachnique intruders use to make their networks or Internet transmission appear legitimate to a victim computer or network. There are ways to prevent the different kinds of virus in computers like firewall it is a security system consisting of hardware and or software that prevents unathorized intrusion, monitors transmissions to and from computer and informs you to attempted intrusion. intrusion detection software analyzes network traffic, assesses system vulnerabilities and identifies intrusions and suspicious behavior.
3.
Some ways to prevent anuathorized computer access and use by disabling the file, folder and printer sharing on internet connection. use a user name with unique combination of characters that identifies user and make a password this is a private combination of characters associated with the user name that allows access to computer resources. aside from that ypou can also use a biometric device this is to authenticates person's identity using personal characteristics like fingerprints, hand geometry, voice, signature and iris.
4.
Hardware theft  is act of stealing computer equipment and hardware vandalism is an act of defacing or destroying computer equipment to safeguard computer from hardware theft and vandalism must used cables to lock equipment, for notebooks computers use passwords, possessed objects and biometrics as security methods and also password can protect mobile devices.
5. 

Software theft is an act of stealing or illegally stealing software, copying software or intentionally erasing programs, software piracy is illegal duplication of copyrighted software and to protect the
manufacturer's software against piracy they should have a license agreement this is an agreement in which users have the right to use the software legally and single-user liscense agreement allows user to install software on one computer, make backup copy, and sell software after removing from computer. Another way is the product activation which allows user to input product identification number online by telephone and receive unique installation identification number.

6.
Encryption is to safeguard against information theft, process of converting plaintext (readable data) into ciphertext (unreadable characters) it is necessary because it often uses more than one method the Encryption key (formula), to read the data, the recipient must decrypt, or decipher the data.
7.
System failure is a prolonged malfunction of computer cause by aging hardware, natural disasters, or electrical power disturbances to protect the system from the said failure devices are available to protect the computer like surge protector it protects computer and equipment from electrical power disturbances and also uninterruptible power supply (UPS) is urge protector that provides power during power loss.
8.
Backup is a duplicate of file, program or disk, there are three options available for backing up computer the full back up of all files in computer, selective back up select which files to back up and three generation back up it preseves three copies of important files. ,in case of system failure or corrupted files restore files by copying to original location.
9.
10.
directly affects our vision and other parts and also our social life some of these are coputer vision syndrom (CVS) this is the eye and vision problems, the
repetitive strain injury (RSI) or the carpal tunnel syndrom (CTS) the inflammation of nerve that connects forearm to palm and tendonitis the inflammation of tendon due to repeated motion and the third one is Computer addiction it is when computer consumes entire social life. but there are some ways to prevent this health-related disorders such as spreading fingers apart for several seconds while keeping wrists straight, gently push back fingers and then thumb, dangle arms loosely at side and then shake arms and hands. To ease eyestrain while working at the computer, you must have take an eyebreak every 10-15 minutes look into the distance and focus on an object for 20-30 seconds, roll your eyes in complete circle, close your eyes and rest them at least for one minute, blink your eyes every five seconds, place your display device about an arm's lenght away from your eyes with the top of the screen at eye level or below, use large fonts, if you wear glasses, ask your doctor about computer glasses and adjust the lighting.

11.
Intellectual property is the right to which creators are entitled for their work, Codes od conduct is a written guidelines that helps determine whether computer action is ethical and employers can distribute to their employess in order to them to have a guide.
12.
Information privacy is the right of individuals and companies to deny or restrict collection and use of information about them yet today,  it is difficult because data is stotred online, employee monitoring is using computers to observe employee computer use and it is legal for employers to use monitoring software programs.  Electronic profile is a data collected when you fill out form on Web and there are merchants sell your electronic profile, often times you can specify whether you want personal information distributed. Cookies are small text file on your computer that contains data about you, some Web sites sell or trade information stored in the cookies and set browser to accept cookies promt you to accept cookies, or disable cookies. Spyware is a program placed on computer without user's knowledge while adware is a program that displays online advertisement. Spam is unsolicited e-mail messages sent to many recipients. Phishing is scam in which perpetrator sends an official looking e-mail that attempts to obtain your personal and financial information.

Lunes, Agosto 8, 2011

Quiz 8

1.
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies). The term "database" refers both to the way its users view it, and to the logical and physical materialization of its data, content, in files, computer memory, and computer data storage. 




2.

File maintenance techniques- refers to the procedures that keep data current. File maintenance procedures include adding records to correct inaccurate data or to update old data with new data, and deleting records when they no longer are needed.

Validation is the process of comparing data with a set of rules or values to find out if the data is correct. Many programs perform a validity check that analyzes data, either as you enter it or after you enter it, to help ensure that it is correct. Types of validity checks include an alphabetic check, a numeric check, a range check, a consistency check, a completeness check, and a check digit. 



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

Character - Eight bits grouped together in a unit form a byte, and each byte represents a single character, which can be a number, letter, space, punctuation mark, or other symbol.







Field - is a combination of one or more related characters and is the smallest unit of data a user accesses.







Record - is a group of related fields.









File - is a collection of related records stored on a storage medium.







4.
data dictionary contains data about cache file in the database and cache field within those files. A DBMS offers several methods to retrieve and maintain data, such as query languages, query by example, forms, and report generators. A query language is consists of simple, English-like statements that allow users to specify the data to display, print, or store. A query by example (QBE) has a graphical user interface that assists users with retrieving data. A form is a window on the screen that provides areas for entering or modifying data. A report generator allows users to design a report on the screen, retrieve data into the report design, and display or print the report. 

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.
File processing approach - each department or area within an organization has its own set of data files.Two major weaknesses of file processing systems are redundant data and isolated data.

























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.

Relational database-stores data in tables that consists of rows and columns. Each row has a primary key and each column has a unique name.
Object-oriented database (OODB) - stores data in objects;often use an object query language to manipulate and retrieve data.














Multidimensional database-stores data in dimensions;allows users to access and analyze any view of the database data and no standard query language exists.









7.
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. 

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

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


Database Analysts and Database Administrators are responsible for managing and coordinating all database activities.


Database Analysts (DA) - focuses on the meaning and usage of data. The DA decides on the placement of fields, defines the relationships among data, and identifies user's access privilege.


Database Administrators (DBA) requires a more technical inside view of the data. The DBA creates and maintains the data dictionary, manages data security, monitors database performance, and checks backup and recovery procedures. 


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 issues their network or computer may have that can allow users unauthorized access to their computer. Below are 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.





Lunes, Agosto 1, 2011

Quiz 7

1.
Computer communications describes a process in which two or more computers or devices transfer data, instructions, and information


Sending
device — initiates
instruction to
transmit data,
instructions, or information
Communications
device — connects
the sending device to
the communications
channel
Communications
channel — media
on which data,
instructions, or information level

Communications
device — connects
the communications
channel to the
receiving device
Receiving
device — accepts
transmission of data,
instructions, or
information


2.
  North/South Bridge
Memory controller
A computer is a miniaturized information highway.
All devices in the computer sends information back and forth.


3.


Users can send and receive wireless messages using wireless.


        Text messaging allows users to send and receive short text messages on a phone or other mobile device or computer


      Picture messaging allows users to send pictures and sound files


 Video messaging allows users to send short video clips


    Wireless instant messaging allows wireless users to exchange real-time messages with one or more other users


        Wireless Internet access points allow people to connect wirelessly to the Internet from home, work, school, and in many public locations


         A cybercafé is a coffeehouse, restaurant, or other location that provides personal computers with Internet access to it customers.


    A global positioning system (GPS) is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order to determine the GPS receiver’s geographic location.

4. List Advantages of using Network
  • share software
  • share information with others on networks
  • share peripherals
  • speed of sharing software and information files
  • cheaper than buying individual software and hardware for each standalone especially if for a school, network software often offers deals for amount being purchased
  • security, files can be copy inhibit mode
  • centralized software management- software being loaded onto one computer but also this loads software to entire network at one time
  • electronic mail(e-mail) between network users, ideal for office memos
  • flexible access- access you files from any computer on the network unlike standalone which would mean only being able to access your data from the one computer you uploaded data 
 5.
A client/server
network
  •  One or more computers act as
  • server (host) and other
  • computers, or clients, access
  • server
  •  Servers – control resources
  •  Clients – rely on servers for
  • resources
  •  Dedicated servers
  • servers, Network Server, Web Server
  •  Efficient for 10 or more computers

Peer-to-peer
network

 Simple network that
connects fewer than
10 computers
 Each computer, or peer,
has equal capabilities
 Ideal for small business










Internet peer-to-peer
(P2P)
Next
 Sometimes called a file
sharing network
 Enables users to
connect to each other’s
hard disks and
exchange files directly






6.
Network Communication Standards
e Network standards defines:
 Way devices access the medium
 Speed on different types of networks
 Types of network technology (cable / wireless)
e 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
Ethernet
 Standard that defines how devices are connected to LAN (bus or star
network)
 Device can transmit data only when the network is available to receive
data.
 If two devices attempt to send at same time collision occurs and should
be retransmitted
 Use cable to transmit data
 Original Ethernet – 10 Mbps
 Fast Ethernet – 100Mbps
 Gigabit Ethernet – 1Gbps
 10-Gigabit Ethernet – 10Gbps
 40-Gigabit Ethernet, 100-Gigabit Ethernet
Token Ring
 Standard for LAN (ring, star)
 Computers share / pass a special signal – token in
unidirectional manner
 Token – series of bits and functions like a ticket
 Whoever has the token can transmit the data
 Supports upto 72 devices
 Using special kind of wiring upto 260 devices
 Data rate – 4 Mbps, 16 Mbps, 100 Mbps and 1Gbps
What are TCP/IP
 TCP/IP (Transmission Control Protocol/Internet Protocol)
technology transmits data by breaking it up into small pieces, or
packets
 Packet – source, destination, sequence information, packet size etc.
 Checking and detecting error
 Sequencing
 Flow Control
• Packet switching : breaking a message, sending it throught best route, reassambling
IEEE 802.11, (Wireless Fidelity Wi-Fi) is a family of standards for
wireless LANs
How two wireless device communicate
Radio waves
Also known as wireless Ethernet
 Can communicate with Ethernet network
Coverage
• 100 ft. in closed area
• 300 ft. in open area

Bluetooth
- Short-range radio waves transmit data between Bluetooth devices
- Transfer rates : 3Mbps
- Coverage : 33 ft (10 m) upto 100 m with additional equipments
- smart phones, headsets, keyboards, digital cameras
- bluetooth adapter
UWB (ultra-wideband)
- short-range radio waves
- Coverage / Rate
10m (33 feet) – 110 Mbps, 2m (6.5 feet) - 480Mbps
- suitable for audio / video / picture files transfer
IrDA (Infrared data association)
- Use Infrared(IR) waves
- 115Kbps – 4 Mbps
- device must be in line of sight
RFID (radio frequency identification)
- radio waves
- specifies how a device communicates with a tag placed on person, animals, objects
- RFID tag (transponder) – memory chip + antenna.
- RFID reader (transceiver) reads the radio signal broadcast by the antenna ;
- Coverage 5 inches – 15 feet
WiMAX (Worldwide Interoperability for Microwave Access) IEEE 802.16
- WiMAX towers can cover up to 30 miles radius
- Fixed WiMAX Rate of transfer : 40Mbps
- Mobile WiMAX Rate : 15Mbps
WAP (Wireless Application Protocol)
- used by devices such as smart phones to display Websites, e-mail, chat rooms, instant
messengers etc.
7.
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. These software send and receive 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.
Telephone network (PSTN)?

 Worldwide telephone
system that handles
voice-oriented
telephone calls
 Can be used for data
communication as




Dial-up line
Next
 Temporary connection using telephone line for
communications
 Costs no more than making regular call
 dial-up modem




Dedicated line
Next
 Five types of digital
dedicated lines are
ISDN line, DSL,
FTTP, T-carrier line,
and ATM
 Always-on connection
between two
communications
devices


9.


Communications devices












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
•Send and receive digital data from DSL(Digital Subscriber Line) / ISDN
(Integrated Service Digital Network) line


•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
 Routers forward data on
Internet using fastest available
path
 Some routers have a built-in
firewall


10.



Before you start:
 To decide what type of network to set up or to find out what hardware and cables you need. 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.

Note

This information is designed for people who have a broadband connection (usually DSL or cable) to the Internet rather than a dial-up connection.

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. For more information.
If you already have an Internet connection, you just need to verify that the connection is working. To do that, open your web browser and go to a website that you don't usually visit. (If you go to a website that you visit often, some of its webpage’s might be stored on your computer and will display correctly even if your connection is faulty.) If the website opens and you don't get any error messages, your connection is working.

Connect the computers

There are several ways to connect computers—the configuration depends on the type of network adapters, modem, and Internet connection that you have. It also depends on whether or not you want to share an Internet connection among all the computers on the network. The following sections briefly describe some connection methods.
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 Picture of 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.

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 Picture of the Start button, and then click Network. You should be able to see icons for the computer you are on and all of the other computers and devices that you have added to the network. If the computer you are checking has a printer attached, the printer icon might not be visible on other computers until you enable printer sharing. (Printer sharing is not available on Windows Vista Starter.)

Note

It might take several minutes for computers running previous versions of Windows to appear in the Network folder.





11.


Physical Transmission Media


Twisted-pair cable and coaxial cable?
Next
 Twisted-pair cable is used for telephone
systems and network cabling
 Separately insulated wires are twisted together
in a pair
 Twisting reduce the noise (disturbances)























 Coaxial cable is often used for cable
television wiring
 Single Copper wire in center
 Insulation
 Woven or braided metal
 Outer cover

























Fiber-optic cable




 Hundreds of thin strands
of glass or platic
 Capable of carrying
significantly more
data at faster speeds
than wire cables
 Less susceptible
to interference
(noise) and, therefore,
more secure
 Faster transmission
 Smaller size (thinner
and lighter)
 Disadvantage : Costly and difficult to install