Are programs that copy themselves repeatedly into a computers memory or disk drive and viruses are deviant programs that can destroy data?

Unit 5: Communications, Networks, and Cyberthreats

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.

From the Analog to the Digital Age

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.

• 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 an analog wave’s amplitude or its frequency.

Networks

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

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.)

Network Architecture: How Networks Are Structured

1. Client/Server a. Consists of clients, which are computers that request data, and servers, which are computers that supply data. b. File servers act like a network-based shared disk drive. c. Database servers store data but don’t store programs. d. Print servers connect one or more printers and schedule and control printnjobs. e. Mail servers manage email.
2. Peer-to-Peer (P2P) a. All computers on the network are “equal” and communicate directly with one another, without relying on servers.

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’svarious sites) but on a private basis, via encryption and authentication; regular I 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.

Network Components — all networks have several things in common:

o wired = twisted-pair, coaxial cable, fiber-optic cable o 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)
• The protocol in your communications software specifies how receiver devices will acknowledge sending devices, a matter called handshaking. Handshaking establishes the fact that the circuit is available and operational. It also establishes the level of device compatibility and the speed of transmission.
• In addition, protocols specify the type of electronic connections used, the timing of message exchanges, and error-detection techniques.
• Each packet, or electronic message, carries four types of information that will help it get to its destination;

1. the sender’s address (IP)
2. the intended receiver’s address
3. how many packets the complete message has been broken into
4. the number of this particular packet. The packets carry the data in the protocols that the Internet uses— that is, TCP/IP

Network linking devices:

• Switch—Device that connects computers to a network; sends only to intended recipients; operates back and forth at the same time.
• Bridge—Interface device that connects same type of networks.
• Gateway—Interface device that connects dissimilar networks.
• Router—Device that directs messages among several networks, wired or and/or wireless.

o Speeds of about 320 megabits per second

• Homeplug o Uses existing home electrical lines o Speeds of 200 megabits per second

Wireless Communications Media

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

Radiofrequency (RF) spectrum is the part of the electromagnetic spectrum that carries most communications signals.

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 o Transmission rate 1 megabits per second or less
• Broadband: For high-speed data and high-quality audio and video; wide band of frequencies o Transmission rate 1 megabits per second to 1 gigabit per second or more 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.

Five Types of Wireless Communications Media

• Infrared Transmission o Sends signals using infrared light (TV remotes) o Frequencies are too low to see (1-16 megabits per second)
• Broadcast Radio o AM/FM, CB, ham, cellphones, police radio o Sends data over long distances using a transmitter and a receiver (up to 2 o megabits per second)
• Cellular Radio o Form of broadcast radio o Widely used in cellphones and wireless modems o Transmits voice and digital messages
• Microwave Radio o Superhigh-frequency radio transmit voice and data at 45 megabits per second o Requires line-of-sight transmitters and receivers o More than ½ of today’s telephones systems use microwave
• Communications Satellites o Microwave relay stations in orbit around the earth o Basis for Global Positioning Systems (GPS) o Cover broad service area o Can be placed at different heights: GEO, MEO, LEO o 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 o MEO – medium-earth orbit

▪ 5,000 – 10,000 miles up o LEO – low-earth orbit ▪ 200 – 1,000 miles up ▪ Has no signal delay

Long-Distance Wireless: One-Way Communication

• GPS (Global Positioning System) o 24 to 32 MEO satellites continuously transmitting timed radio signals to identify Earth locations o Each satellite circles earth twice each day at 11,000 miles up o GPS receivers pick up transmissions from up to 4 satellites and pinpoint the receiver’s location o Accurate within 3 – 50 feet, with a norm of 10 feet accuracy o Not all services based on GPS technology are reliable
• One-way Pagers: radio receivers that receive data sent from a special radio transmitter o Radio transmitter sends out signals over the special frequency; pagers are tuned to that frequency o When a particular pager hears its own code, it receives and displays the message o Often used in hospitals and areas where smartphones are not allowed

Long-Distance Wireless: Two-Way Communication

• 1G: First-Generation Cellular Service o Analog cellphones o Designed for voice communication using a system of hexagonal groundarea cells around transmitter- receiver cell towers o Good for voice – less effective for data because of handing off
• 2G: Second-Generation Cellular Service o Uses digital signals o First digital voice cellular network
• 3G: Third-Generation Cellular Service o Broadband technology o Carries data at high speeds: 144 kilobits per second up to 3 megabits per second o Accepts e-mail with attachments o Displays color video and still pictures o Plays music
• 4G: Fourth-Generation Cellular Service o A nationwide 4G network is in development; up to 100 megabits/second o Enables faster Internet surfing o 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.

Short-Range Wireless: Two-Way Communication

• Local Area Networks o Range 100 – 228 feet o Include Wi-Fi (802) type networks o Wi-Fi n is the latest and fastest Wi-Fi technology

• Personal Area Networks o Range 30 – 33 feet o Use Bluetooth, ultra wideband, and wireless USB

• Home Automation networks o Range 100 – 150 feet o Use Insteon, ZigBee, and Z-Wave standards

• Wi-Fi b, a, g, & n for local area networks (LANs)

• 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.

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

• Employees
• Outside partners & suppliers
• Hardware thieves
• Con artists, scammers, & counterfeiters

Cyberattacks & Malware

• 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

Cyberthreats:

• Denial of Service Attack o Consists of making repeated requests of a computer or network device, thereby overloading it and denying access to legitimate users. o Used to target particular companies or individuals.
• Virus o 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. o Usually attached to an executable file that you must run or open (to activate the virus).
• Worms o A program that copies itself repeatedly into a computer’s memory or disk drive. o May copy itself so much it crashes the infected computer.
• Trojan Horses o 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. o Backdoors and spyware allow others to access your computer without your knowledge.
• Rootkits o In many computer operating systems, the “root” is an account for system administration. A “kit” is the malware secretly introduced into the computer. A rootkit gives an attacker “super powers” over computers—for example, the ability to steal sensitive personal information.
• Blended Threats o A blended threat is a more sophisticated attack that bundles some of the worst aspects of viruses, worms, Trojan horses, and other malware into one single threat. Blended threats can use server and Internet vulnerabilities to initiate, then transmit and also spread an attack. Blended threats are designed to use multiple modes of transport—email, flash drives, networks, and so on.
• Zombies & Bots o A botmaster uses malware to hijack hundreds to many thousands of computers and is able to remotely control them all, including the ability to update the malware and to introduce other programs such as spyware. o Hijacked computers are called zombies. o A botnet (robot network) is a network of computers in which each computer has been implanted with instructions to wait for commands from the person controlling the botnet.
• Ransomeware

o A botnet may be used to install ransomeware, which holds the data on a computer or the use of the computer hostage until a payment is made. Ransomware encrypts the target’s files, and the attacker tells the victim to make a payment of a specified amount to a special account to receive the decryption key.

• Cellphone Malware o Spread via Internet downloads, MMS attachments, and Bluetooth transfers o Usually show up disguised as applications such as games, security patches, add-on functionalities, erotica, and free programs

Time, Logic, & Email Bombs

A time bomb is malware programmed to “go off” at a particular time or date. A logic bomb is “detonated” when a specific event occurs—for example, all personnel records are erased when an electronic notation is made that a particular person was fired. Email bombs overwhelm a person’s email account by surreptitiously subscribing it to dozens or even hundreds of mailing lists.

• Phone Malware: Worms and viruses and other malware are attacking smartphones. The most common type of cellphone infection occurs when a cellphone downloads an infected file from a PC or the Internet, but phone-to- phone viruses are also on the rise.
• Infected files usually show up disguised as applications such as games, security patches, add-on functionalities, and free stuff.

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
• 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

Encryption

• Process of altering readable data into unreadable form to prevent unauthorized access o Uses powerful mathematical ciphers to create coded messages that are difficult to break o Unencrypted messages are known as plain text o Encrypted text is known as cybertext o You use an encryption key to encrypt and decrypt codded messages

Concerns about Privacy& Identity Theft

• 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: o Name migration o Résumé rustling & online snooping o Government prying & spying

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

Check your computer performance /hardware 1. Click Start 2. Control Panel 3. System 4. System & Security 5. General 6. You will be able to see processor speed and RAM (but you won’t know how well they perform)

How to Speed Up your computer using windows tool

• Uninstall redundant programs
• Reduce the programs that unnecessarily automatically start
• Purge unnecessary files
• Troubleshoot windows
• Check windows event viewer

How to Speed Up your computer using Good Practices

• Keep PC physically clean by removing dust and any dirt obstacles in the way of the ventilation and on the screen
• Shut Down the PC every so often to prevent application build up and slowdowns

Upgrading your PC to increase speed

• Look at the bottlenecks, these are usually the least performing hardware on the computer
• You can use user benchmark to compare your existing hardware to potential hardware upgrades

Unit 7: The Challenges of the Digital Age: Society & Information Technology Today

Technology is now used to develop predictive search apps —applications that know what you want before you do. Some people, however, see the new technology as just the latest intrusion into our private lives, mining digital personal information about us whose uses we cannot always foresee.

Security Issues: Errors, Accidents, & Natural Hazards

• Human errors o Humans often are not good at assessing their own information o Human emotions affect performance; people get frustrated o Human perceptions are slower than the equipment o Information overload may also be a problem
• Procedural errors o When people fail to follow established procedures, errors can occur
• Software errors o Software bug: an error in a program that causes it not to work properly
• “Dirty data” problems o Incomplete, outdated, or otherwise inaccurate data
• Electromechanical problems o Mechanical systems can wear out or become damaged o They can also be badly designed or constructed o Power failures and surges can damage equipment
• Natural hazards can lead to disasters
• Computer Crimes o Two types of computer crime: ▪ Illegal act perpetrated against computers or telecommunications (computer is the target)

▪ Use of computers or telecommunications to accomplish an illegal act (computer is the tool) o Theft of hardware o Theft of software o Theft of intellectual property (piracy) o Theft of time and services o Theft of information (e., medical info, credit card info) o Internet-related fraud (e., Wi-Fi phishing, or evil twin attack) o Crimes of malice: crashing entire systems ▪ Attacks on power-control systems and attacks on the Internet

Security Safeguards

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

• Computer security’s five components:
  1. Deterrents to computer crime
  2. Identification and access
  3. Encryption
  4. Protection of software and data
  5. Disaster recovery plans

Deterrents to computer crime

• Enforcing laws
• CERT: The Computer Emergency Response Team o Provides round-the-clock information on international computer security threats
• Tools to fight fraudulent and unauthorized online uses o Rule-based detection software o Predictive-statistical-model software o Employee Internet management software o Internet filtering software o Electronic surveillance

Identification and access

• Verify legitimate right of access by what you have, what you know, and who you are
• What you have: cards, keys, signatures, badges
• What you know: PINs and passwords; callback provision
• Who you are: biometrics (such as hand geometry, fingerprint scans, iris recognition, face recognition, voice recognition)

Encryption

• The process of altering readable data into unreadable form to prevent unauthorized access
• Advantage: encrypting data that is available over the Internet keeps thieves and crackers from reading it
• Disadvantage: encrypting data may prevent law-enforcement officials from reading the data criminals are sending to one another

Protection of software and data

• Restrict access to online files; use transaction logs
• Use audit controls to track who used what programs and servers, which files were opened, and so on

Are programs that copy themselves repeatedly into a computer's memory or disk drive and viruses are deviant programs that can destroy data?

What is the difference between a virus and a worm quizlet?

What is true of the malware Trojan horse quizlet?