PPT

GSAS222Unit6_PPT.pptx

Chapter 6

Communications, Networks, & Cyberthreats

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Introduction to Information Technology

Chapter Topics

UNIT 6A: Networks & Wired & Wireless Data

6.1 From the Analog to the Digital Age

6.2 Networks

6.3 Wired Communications Data

6.4 Wireless Communications Media

UNIT 6B: Cyberthreats, Security, & Privacy Issues

6.5 Cyberintruders: Trolls, Spies, Hackers, & Thieves

6.6 Cyberattacks & Malware

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

Digital convergence is the gradual merger of computing and communications into a new information environment, in which the same information is exchanged among many kinds of equipment, using the language of computers.

At the same time, there has been a convergence of several important industries—computers, telecommunications, consumer electronics, entertainment, mass media— producing new electronic products that perform multiple functions.

Introduction to Information Technology

6.1 From the Analog to the Digital Age

Introduction to Information Technology

Digital

Computers use digital signals—0s and 1s, off and on.

All the data that a computer processes is a series of

0s and 1s.

Each signal is a bit.

Analog

But most phenomena in life are analog.

Analog signals use wave variations, continuously changing.

Sound, light, and temperature are analog forms.

Traditional TV and radio use analog signals.

Humans’ vision operates in analog mode.

But analog data can be converted into digital form. Even though digital data is not as exact as analog data, it is easier to manipulate.

Introduction to Information Technology

For data transmission over telephone lines and cables, modems are needed to convert analog data into digital data that computers can use.

Modem is short for modulate/demodulate. Modems modulate (convert) a computer’s digital data to analog data, transmit it, then demodulate (reconvert) it back to digital data for the receiving computer.

Modems can convert data by modulating either a analog wave’s amplitude or its frequency.

Introduction to Information Technology

Chapter Topics

UNIT 6A: Networks & Wired & Wireless Data

6.1 From the Analog to the Digital Age

6.2 Networks

6.3 Wired Communications Data

6.4 Wireless Communications Media

UNIT 6B: Cyberthreats, Security, & Privacy Issues

6.5 Cyberintruders: Trolls, Spies, Hackers, & Thieves

6.6 Cyberattacks & Malware

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

6.2 Networks

Introduction to Information Technology

Network: system of interconnected computers, telephones, and/or other communications devices that can communicate with one another and share applications and data.

Benefits of Networks

Share peripheral devices, such as printers, scanners, disk drives

Share software

Share data and information

Better communications

Accessing databases

Centralized communications

Security of information, because of improved backup systems

Introduction to Information Technology

Types of networks: WANs, MANs, & Others

Wide area network (WAN): Communications network that covers a wide geographic area, such as a country or the world. Most long-distance and regional telephone companies are WANs. WANs are used to connect local area networks. The best example of a WAN is the Internet.

Metropolitan area network (MAN): Communications network covering a city or a suburb. Many cellphone systems are MANs.

Local area network (LAN): Connects computers and devices in a limited geographic area, such as one office, one building, or a group of buildings close together. LANs are the basis for most office networks, and the organization that runs the LAN owns it. WANs and MANs generally use a common carrier—a telecommunications company that hires itself out to the public to provide communications transmission services—for at least part of its connections. (A home area network is a LAN.)

(continued)

Introduction to Information Technology

UPDATE

Introduction to Information Technology

Network Architecture: How Networks Are Structured

1. Client/Server

Consists of clients, which are computers that request data, and servers, which are computers that supply data.

File servers act like a network-based shared disk drive.

Database servers store data but don’t store programs.

Print servers connect one or more printers and schedule and control print jobs.

Mail servers manage email.

2. Peer-to-Peer (P2P)

All computers on the network are “equal” and communicate directly with one another, without relying on servers.

Introduction to Information Technology

Intranets, Extranets, & VPNs: Use the Internet as their base

Intranets—use infrastructure and standards of the Internet and the web, but for an organization’s internal use only.

Extranets—similar to intranets but allows use by selected outside entities, such as suppliers.

VPNs (virtual private networks): use a public network (usually the Internet) plus intranets and extranets to connect an organization’s various sites) but on a private basis, via encryption and authentication; regular Internet users do not have access to the VPN’s data and information.

All use firewalls for security, a system of hardware and/or software that protects the system from intruders.

Introduction to Information Technology

Network Components — all networks have several things in common:

wired = twisted-pair, coaxial cable, fiber-optic cable

wireless = infrared, microwave, radio, Wi-Fi, satellite

Hosts and Nodes: Client/server network has a host computer, which controls the network; a node is any device attached to the network.

Packets—fixed-length blocks of data for transmission, reassembled after transmission.

Protocols—set of conventions, or rules, governing the exchange of data between hardware and/or software components in the network; built into the hardware or software you are using. (continued)

Introduction to Information Technology

Each packet, or electronic message, carries four types of information that will help it get to its destination;

the sender’s address (IP)

the intended receiver’s address

how many packets the complete message has been broken into

the number of this particular packet. The packets carry the data in the protocols that the Internet uses—that is, TCP/IP

Introduction to Information Technology

Network topology: The layout (shape) of a network

Star – all nodes are connected through a central network switch

Ring – all nodes are connected in a continuous loop

Bus – all nodes are connected to a single wire or cable

Tree – a bus network of star networks

Mesh – messages sent to the destination can take any possible shortest, easiest route to reach its destination. There must be at least two paths to any individual computer to create a mesh network. (Wireless networks are often implemented as a mesh, and the Internet is a mesh.)

Introduction to Information Technology

Star Network

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Ring Network

Introduction to Information Technology

Bus Network

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Ethernet

Ethernet is a LAN technology that can be used with almost any kind of computer and that describes how data can be sent between computers and other networked devices usually in close proximity.

Commonly used in star topologies.

Introduction to Information Technology

Chapter Topics

UNIT 6A: Networks & Wired & Wireless Data

6.1 From the Analog to the Digital Age

6.2 Networks

6.3 Wired Communications Data

6.4 Wireless Communications Media

UNIT 6B: Cyberthreats, Security, & Privacy Issues

6.5 Cyberintruders: Trolls, Spies, Hackers, & Thieves

6.6 Cyberattacks & Malware

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

6.3 Wired Communications Media

Introduction to Information Technology

Communications media are the means of interchanging or transmitting and receiving information.

A. Twisted-Pair Wire (dial-up connections)

2 strands of insulated copper wire twisted around each other

Twisting reduces interference (crosstalk) from electrical signals

Data rates are 1 – 128 megabits per second (slow)

B. Coaxial Cable

Insulated copper wire wrapped in a metal shield and then in an external plastic cover

Used for cable TV and cable Internet electric signals

Carries voice and data up to 200 megabits per second

C. Fiber-optic cable

Dozens or hundreds of thin strands of glass or plastic that transmit pulses of light, not electricity

Can transmit up to 2 gigabits per second (very fast)

Have lower error rate than twisted-pair or coax

More expensive than twisted-pair or coax

Lighter and more durable than twisted-pair or coax

More difficult to tap into than twisted-pair or coax

Introduction to Information Technology

Chapter Topics

UNIT 6A: Networks & Wired & Wireless Data

6.1 From the Analog to the Digital Age

6.2 Networks

6.3 Wired Communications Data

6.4 Wireless Communications Media

UNIT 6B: Cyberthreats, Security, & Privacy Issues

6.5 Cyberintruders: Trolls, Spies, Hackers, & Thieves

6.6 Cyberattacks & Malware

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

6.4 Wireless Communications Media

Introduction to Information Technology

Electromagnetic spectrum of radiation is the basis of all telecommunications signals, wired and wireless.

Radio-frequency (RF) spectrum is the part of the electromagnetic spectrum

that carries most communications signals.

Introduction to Information Technology

Bandwidth: range (band) of frequencies that a transmission medium can carry in a given period of time

Analog bandwidth is expressed in hertz, digital bandwidth usually in bits per second (bps)

Narrowband (voiceband): used for regular telephone communications

Transmission rate 1.5 megabits per second or less

Broadband: For high-speed data and high-quality audio and video; wide band of frequencies

Transmission rate 1.5 megabits per second to 1 gigabit per second or more

Introduction to Information Technology

TC/IP (Ch. 2) is the protocol for getting wired devices connected to the Internet

WAP (wireless application protocol): Wireless handheld devices such as cellphones use the Wireless Application Protocol for connecting wireless users to the Web. Just as the protocol TCP/IP was designed to provide a wired connection to your Internet access provider, WAP is a standard designed to link nearly all mobile devices telecommunications carriers’ wireless networks and content providers.

Introduction to Information Technology

Infrared Transmission

Sends signals using infrared light (TV remotes)

Frequencies are too low to see (1-16 megabits per second)

Broadcast Radio

AM/FM, CB, cellphones, police radio

Sends data over long distances using a transmitter and a receiver (up to 2 megabits per second)

Cellular Radio

Form of broadcast radio

Widely used in cellphones and wireless modems

Transmits voice and digital messages

Microwave Radio

Superhigh-frequency radio transmit voice and data at 45 megabits per second

Requires line-of-sight transmitters and receivers

More than ½ of today’s telephones systems use microwave

Communications Satellites

Microwave relay stations in orbit around the earth

Basis for Global Positioning Systems (GPS)

Cover broad service area

Five Types of Wireless Communications Media

Introduction to Information Technology

Communications Satellites (continued)

Can be placed at different heights: GEO, MEO, LEO

GEO – geostationary earth orbit

22,300 miles above earth; travel at the same speed as the earth and so appear to us to be stationary

Always above equator

Transmission delay (latency) can make conversations difficult; not good for applications requiring real-time user input

MEO – medium-earth orbit

5,000 – 10,000 miles up

LEO – low-earth orbit

200 – 1,000 miles up

Has no signal delay

Introduction to Information Technology

Long-Distance Wireless: One-Way Communication

GPS (Global Positioning System)

24 to 32 MEO satellites continuously transmitting timed radio signals to identify Earth locations

Each satellite circles earth twice each day at 11,000 miles up

GPS receivers pick up transmissions from up to 4 satellites and pinpoint the receiver’s location

Accurate within 3 – 50 feet, with a norm of 10 feet accuracy

Not all services based on GPS technology are reliable

Introduction to Information Technology

Long-Distance Wireless: One-Way Communication (continued)

One-way Pagers: radio receivers that receive data sent from a special radio transmitter

Radio transmitter sends out signals over the special frequency; pagers are tuned to that frequency

When a particular pager hears its own code, it receives and displays the message

Often used in hospitals and areas where smartphones are not allowed

Introduction to Information Technology

Long-Distance Wireless: Two-Way Communication

1G: First-Generation Cellular Service

Analog cellphones

Designed for voice communication using a system of hexagonal ground-area cells around transmitter-receiver cell towers

Good for voice – less effective for data because of handing off

2G: Second-Generation Cellular Service

Uses digital signals

First digital voice cellular network

Introduction to Information Technology

Long-Distance Wireless: Two-Way Communication (continued)

3G: Third-Generation Cellular Service

Broadband technology

Carries data at high speeds: 144 kilobits per second up to 3.1 megabits per second

Accepts e-mail with attachments

Displays color video and still pictures

Plays music

Introduction to Information Technology

Long-Distance Wireless: Two-Way Communication (continued)

4G: Fourth-Generation Cellular Service

A nationwide 4G network is in development; up to 100 megabits/second

Enables faster Internet surfing

Includes LTE (Long Term Evolution), an international standard widely adopted in the United States and several countries in Europe and Asia. LTE supports data transfer rates of up to 100 megabits per second over cellular networks.

Introduction to Information Technology

Cellphone Connections

Short-Range Wireless: Two-Way Communication

Local Area Networks

Range 100 – 228 feet

Include Wi-Fi (802.11) type networks

Wi-Fi n is the latest and fastest Wi-Fi technology

Personal Area Networks

Range 30 – 33 feet

Use Bluetooth, ultra wideband, and wireless USB

Home Automation networks

Range 100 – 150 feet

Use Insteon, ZigBee, and Z-Wave standards

Introduction to Information Technology

Wi-Fi setup in a restaurant

Introduction to Information Technology

General Wi-Fi Network

UNIT 6B: Cyberthreats: Trolls, Spies, & Hackers & Thieves

The ongoing dilemma of the Digital Age is balancing convenience against security.

Security consists of safeguards for protecting information technology against unauthorized access, system failures, and disasters that can result in damage or loss.

Introduction to Information Technology

Chapter Topics

UNIT 6A: Networks & Wired & Wireless Data

6.1 From the Analog to the Digital Age

6.2 Networks

6.3 Wired Communications Data

6.4 Wireless Communications Media

UNIT 6B: Cyberthreats, Security, & Privacy Issues

6.5 Cyberintruders: Trolls, Spies, Hackers, & Thieves

6.6 Cyberattacks & Malware

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

6.5 Cyberintruders

Trolls, Spies, Hackers, & Thieves

Introduction to Information Technology

Trolls aren’t necessarily destructive, but they can be disruptive on online comment boards.

A troll is a person who posts intentionally offensive, incendiary, or off-topic comments online, to upset people.

Many companies have extensive data-collection efforts that constantly track (spy on) our personal activities.

Introduction to Information Technology

Malicious hackers break into computers for malicious purposes.

Script kiddies are technically unsophisticated teenagers who use downloadable software for perform break-ins.

Hacktivists are hacker activists who break into systems for a political or a socially motivated purpose.

Black-hat hackers break into computers to steal or destroy information or to use it for illegal profit.

Cyberterrorists attack computer systems so as to bring physical, political or financial harm to groups, companies, or nations.

Benign hackers (thrill-seeker hackers) illegally access computer systems simply for the challenge of it, not to damage or steal anything; their reward is the achievement of breaking in.

Benevolent hackers (ethical hackers or white-hat hackers) are usually computer professionals who break into computer systems and networks with the knowledge of their owners to expose security flaws that can then be fixed.

Introduction to Information Technology

Thieves may be a company’s employees or suppliers or professionals.

Employees

Outside partners & suppliers

Hardware thieves

Con artists, scammers, & counterfeiters

Introduction to Information Technology

Chapter Topics

UNIT 6A: Networks & Wired & Wireless Data

6.1 From the Analog to the Digital Age

6.2 Networks

6.3 Wired Communications Data

6.4 Wireless Communications Media

UNIT 6B: Cyberthreats, Security, & Privacy Issues

6.5 Cyberintruders: Trolls, Spies, Hackers, & Thieves

6.6 Cyberattacks & Malware

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

6.6 Cyberattacks & Malware

Introduction to Information Technology

Networks and computer systems are susceptible to attacks by all kinds of malware.

Some common cyberthreats are denial-of-service attacks; viruses; worms; Trojan horses; rootkits and backdoors; blended threats; zombies; ransomware; and time, logic, and email bombs.

Introduction to Information Technology

Cyberthreats:

Denial of Service Attack

Consists of making repeated requests of a computer or network device, thereby overloading it and denying access to legitimate users.

Used to target particular companies or individuals.

Virus

Deviant program that hides in a file or a program on a disk, flash memory drive, in an e-mail, or in a web link and that causes unexpected effects such as destroying or corrupting data.

Usually attached to an executable file that you must run or open (to activate the virus).

Introduction to Information Technology

Cyberthreats (continued)

Worms

A program that copies itself repeatedly into a computer’s memory or disk drive.

May copy itself so much it crashes the infected computer.

Trojan Horses

Programs that pretend to be a useful program such as a free game or a screensaver but that carry viruses or malicious instructions that damage your computer or install a backdoor or spyware.

Backdoors and spyware allow others to access your computer without your knowledge.

Introduction to Information Technology

Cyberthreats (continued)

Cellphone Malware

Spread via Internet downloads, MMS attachments, and Bluetooth transfers

Usually show up disguised as applications such as games, security patches, add-on functionalities, erotica, and free programs

Protect your phone:

Turn off Bluetooth discoverable mode

Check security updates to learn about filenames to watch out for

Install security software

Introduction to Information Technology

Cyberthreats (continued)

How they spread

Via e-mail attachments

By infected disks and flash drives

By clicking on infiltrated websites

By downloading infected files from websites

Through infiltrated Wi-Fi hotspots

From one infected PC on a LAN to another

What can you do about it?

Install antivirus and firewall software

Subscribe to the manufacturer’s automatic antivirus

update service

Introduction to Information Technology

Online Safety

Use antivirus software, and keep it current

Install a firewall to monitor network traffic and filter out undesirable types of traffic and undesirable sites

Don’t use the same password for multiple sites

Don’t give out any password information

Use robust passwords:

Minimum 8 characters with letters, numbers, characters

4cats is not a good password; f0UrK@tTz is safer

Use biometric identification

Use encryption

Introduction to Information Technology

Online Safety (continued)

Install antispyware software

Encrypt financial and personal records so only you can read them

Back up your data, so if your PC is attacked and must be reformatted, you can restore your data

Never download from a website you don’t trust

Consider biometric authentication

Introduction to Information Technology

Online Safety (continued)

Encryption

Process of altering readable data into unreadable form to prevent unauthorized access

Uses powerful mathematical ciphers to create coded messages that are difficult to break

Unencrypted messages are known as plain text

Encrypted text is known as cybertext

You use an encryption key to encrypt and decrypt codded messages

Introduction to Information Technology

6.7 Concerns about Privacy & Identity Theft

Introduction to Information Technology

The proliferation of networks and databases have put privacy under great pressure.

Privacy is the right of people not to reveal information about themselves.

Some threats to privacy:

Name migration

Résumé rustling & online snooping

Government prying & spying

Introduction to Information Technology

Identity (ID) theft, or theft of identity (TOI), is a crime in which thieves hijack your name and identity and use your information and credit rating to get cash or buy things.

Wallet or purse theft

Mail theft

Mining the trash

Telephone solicitation

Insider access to database

Outsider access to database

Introduction to Information Technology

If ID theft happens, contact:

Credit card companies

Your bank

Department of Automotive Vehicles

Utility companies

Phone companies

Local police

Federal Trade Commission

Other organizations you belong to

Introduction to Information Technology