Martes, Agosto 9, 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.

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 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. 

Lunes, Agosto 1, 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 Ø

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.