1 MIS, Chapter 5 ©2013 Course Technology, a part of Cengage Learning PROTECTING INFORMATION RESOURCES CHAPTER 5 Hossein BIDGOLI MIS

1MIS, Chapter 5

©2013 Course Technology, a part of Cengage Learning

PROTECTING INFORMATION RESOURCES

CHAPTER 5

Hossein BIDGOLI

MIS

2MIS, Chapter 5


Chapter 5 Protecting Information Resources

LO1 Describe information technologies that could be used in computer crimes.

LO2 Describe basic safeguards in computer and network security.

LO3 Explain the major security threats.

LO4 Describe security and enforcement measures.

LO5 Summarize the guidelines for a comprehensive security system, including business continuity planning.

l e a r n i n g o u t c o m e s

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Risks Associated with Information Technologies

• Misuses of information technology– Invade users’ privacy – Commit computer crimes

• Minimize or prevent by: – Installing operating system updates regularly– Using antivirus and antispyware software– Using e-mail security features

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Spyware and Adware

• Spyware – Software that secretly gathers information

about users while they browse the Web– Can be used maliciously

• Install antivirus or antispyware software• Adware

– Form of spyware – Collects information about the user to display

advertisements in the Web browser

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Phishing

• Phishing – Sending fraudulent e-mails that seem to come

from legitimate sources

• Direct e-mail recipients to false Web sites – To capture private information

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Keystroke Loggers

• Keystroke loggers– Monitor and record keystrokes – Can be software or hardware devices– Sometimes used by companies to track

employees’ use of e-mail and the Internet – Can be used for malicious purposes

• Some antivirus and antispyware programs protect against software keystroke loggers

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Sniffing and Spoofing

• Sniffing – Capturing and recording network traffic – Often used by hackers to intercept information

• Spoofing – Attempt to gain access to a network by posing

as an authorized user to find sensitive information

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Computer Crime and Fraud

• Computer fraud – Unauthorized use of computer data for personal

gain

• Social networking sites – Used for committing computer crime

• Examples– Denial-of-service attacks – Identity theft – Software piracy – Distributing child pornography – E-mail spamming

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Computer Crime and Fraud (cont’d.)

– Writing or spreading viruses, worms, Trojan programs, and other malicious code

– Stealing files – Changing computer records – Virus hoaxes – Sabotage

• Company insiders commit most computer crimes

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Computer and Network Security: Basic Safeguards

• Critical for most organizations– Especially in recent years, with hackers

becoming more numerous and adept at stealing and altering private information

• Hackers use a variety of tools to break into computers and networks– Sniffers, password crackers, and rootkits– Journals Phrack and 2600: The Hacker

Quarterly

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Computer and Network Security: Basic Safeguards (cont’d.)• Comprehensive security system

– Protects an organization’s resources– Including information and computer and network

equipment, e-mails, invoices transferred via electronic data interchange (EDI), new product designs, marketing campaigns, and financial statements

• Threats:– Include sharing passwords with co-workers, leaving

a computer unattended while logged on to the network, or even spilling coffee on a keyboard

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Computer and Network Security: Basic Safeguards (cont’d.)• Comprehensive security system

– Includes hardware, software, procedures, and personnel that collectively protect information resources

• Confidentiality – System must not allow disclosing information

to anyone who isn’t authorized to access it– Secure government agencies– Businesses– E-commerce

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Computer and Network Security: Basic Safeguards (cont’d.)• Integrity

– Ensures the accuracy of information resources in an organization

– Financial transactions

• Availability – Ensures that computers and networks are

operating– Authorized users can access the information

they need

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Exhibit 5.1 The McCumber Cube

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Computer and Network Security: Basic Safeguards (cont’d.)• Three levels of security

– Level 1: front-end servers– Level 2: back-end systems– Level 3: corporate network

• Fault-tolerant systems– Combination of hardware and software for

improving reliability– Uninterruptible power supply (UPS)– Redundant array of independent disks (RAID) – Mirror disks

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Security Threats: An Overview

• Some threats can be controlled completely or partially, but some can’t be controlled

• Categories– Unintentional– Intentional

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Intentional Threats

• Viruses • Worms • Trojan programs • Logic bombs • Backdoors • Blended threats (e.g., worm launched by

Trojan) • Rootkits • Denial-of-service attacks • Social engineering

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Viruses

• Type of malware • Estimating the dollar amount of damage

viruses cause can be difficult • Usually given names

– I Love You, Michelangelo

• Virus: Consists of self-propagating program code that’s triggered by a specified time or event

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Viruses (cont’d.)

• Seriousness of viruses varies • Transmitted through a network and e-mail

attachments – Bulletin or message boards

• Virus hoaxes – Can cause as much damage as real viruses

• Indications of a computer infected by a virus

• Best measure against viruses – Installing and updating antivirus programs

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Worms

• Travels from computer to computer in a network– Does not usually erase data

• Independent programs that can spread themselves without having to be attached to a host program

• Replicates into a full-blown version that eats up computing resources

• Well-known worms – Code Red, Melissa, and Sasser

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Trojan Programs and Logic Bombs

• Trojan program– Named after the Trojan horse the Greeks used

to enter Troy during the Trojan War – Contains code intended to disrupt a computer,

network, or Web site – Usually hidden inside a popular program

• Logic bomb– Type of Trojan program used to release a virus,

worm, or other destructive code – Triggered at a certain time or by an event

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Backdoors and Blended Threats

• Backdoor– Programming routine built into a system by its author– Enables the author to bypass security and sneak back

into the system later to access programs or files – Users aren’t aware a backdoor has been activated

• Blended threat – Combines the characteristics of several malicious

codes with vulnerabilities on public/private networks – Goal is not to just start/transmit an attack, but to

spread it– Multi-layer security system can guard from threats

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Denial-of-Service Attacks

• Floods a network or server with service requests – Prevent legitimate users’ access to the system

• Target Internet servers • Distributed denial-of-service (DDoS) attack

– Hundreds or thousands of computers work together to bombard a Web site with thousands of requests for information in a short period

– Difficult to trace

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Social Engineering

• Using “people skills” to trick others into revealing private information– Takes advantage of the human element of

security systems

• Use the private information they’ve gathered to break into servers and networks and steal data

• Commonly used social-engineering techniques – “Dumpster diving” and “shoulder surfing”

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Protecting Against Data Theft and Data Loss

• Portable storage media– Theft or loss of media– Stealing company data

• Guidelines to protect against these risks

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Security Measures and Enforcement: An Overview

• Biometric security measures • Nonbiometric security measures • Physical security measures • Access controls • Virtual private networks • Data encryption • E-commerce transaction security

measures • Computer Emergency Response Team

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Biometric Security Measures

• Use a physiological element unique to a person

• Biometric devices and measures– Facial recognition– Fingerprints– Hand geometry– Iris analysis– Palm prints– Retinal scanning– Signature analysis

– Vein analysis – Voice recognition

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Exhibit 5.2 Examples of Biometric Devices

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Nonbiometric Security Measures

• Main security measures:– Callback modems– Firewalls– Intrusion detection systems

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Callback Modems

• Verify whether a user’s access is valid by: – Logging the user off – Calling the user back at a predetermined

number

• Useful in organizations with many employees who work off-site

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Firewalls

• Combination of hardware and software • Acts as a filter or barrier between a private

network and external computers or networks • Network administrator defines rules for access• Examine data passing into or out of a private

network – Decide whether to allow the transmission based on

users’ IDs, the transmission’s origin and destination, and the transmission’s contents

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Exhibit 5.3 Basic Firewall Configuration

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Firewalls (cont’d.)

• Possible actions after examining packet– Reject the incoming packet– Send a warning to the network administrator– Send a message to the sender that the attempt

failed– Allow the packet to enter (or leave) the private

network

• Main types of firewalls – Packet-filtering firewalls– Application-filtering firewalls– Proxy servers

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Exhibit 5.4 Proxy Server

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Intrusion Detection Systems

• Protect against both external and internal access

• Usually placed in front of a firewall • Prevent against DoS attacks• Monitor network traffic• “Prevent, detect, and react” approach• Require a lot of processing power and can

affect network performance

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Physical Security Measures

• Primarily control access to computers and networks

• Include– Cable shielding– Corner bolts– Electronic trackers– Identification (ID) badges– Proximity-release door openers– Room shielding– Steel encasements

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Lost and Stolen Laptops

• Recommendations:– Install cable locks and use biometric measures– Only store confidential data when necessary– Use passwords– Encrypt data– Install security chips

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Access Controls

• Terminal resource security – Software feature that erases the screen and

signs the user off automatically after a specified length of inactivity

• Password – Combination of numbers, characters, and

symbols that’s entered to allow access to a system

– Length and complexity determines its vulnerability to discovery

– Guidelines for effective passwords

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Virtual Private Networks

• Provides a secure “tunnel” through the Internet – For transmitting messages and data via a

private network

• Remote users have a secure connection to the organization’s network

• Low cost• Slow transmission speeds

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Data Encryption

• Transforms data, called plaintext or cleartext, into a scrambled form called ciphertext

• Rules for encryption determine how simple or complex the transformation process should be – Known as the “encryption algorithm”

• Protocols– Secure Sockets Layer (SSL)– Transport Layer Security (TLS)

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Exhibit 5.7 Using Encryption

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Data Encryption (cont’d.)

• Key size– Between 32 and 168 bits

• Main types of encryption– Asymmetric also called “public key encryption”– Symmetric

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E-commerce Transaction Security Measures

• Three factors are critical for security: – Authentication– Confirmation– Nonrepudiation

• Transaction security– Confidentiality– Authentication– Integrity– Nonrepudiation of origin– Nonrepudiation of receipt

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Computer Emergency Response Team

• Developed by the Defense Advanced Research Projects Agency

• Focuses on security breaches and DoS attacks

• Offers guidelines on handling and preventing these incidents

• Cyber Incident Response Capability (CIRC)– http://www.doecirc.energy.gov/aboutus.html

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Guidelines for a Comprehensive Security System

• Train employees• Guidelines and steps involved

– People– Procedures– Equipment and technology

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Business Continuity Planning

• Outlines procedures for keeping an organization operational

• Prepare for disaster• Plan steps for resuming normal operations

as soon as possible

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Summary

• Impact of IT tools on privacy– Use of IT tools to commit computer crimes

• Basic safeguards, fault-tolerant systems– Intentional security threats

• Biometric, nonbiometric, and physical security measures; access controls, firewalls, intrusion detection systems

• Establish comprehensive security system and business continuity plan

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DATA COMMUNICATION: DELIVERING INFORMATION ANYWHERE AND ANYTIME

CHAPTER 6

Hossein BIDGOLI

MIS

49MIS, Chapter 5


Chapter 6 Data Communication: Delivering Information Anywhere and Anytime

LO1 Describe major applications of a data communication system.

LO2 Explain the major components of a data communication system.

LO3 Describe the major types of processing configurations.

LO4 Explain the three types of networks.

LO5 Describe the main network topologies.

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LO6 Explain important networking concepts, such as bandwidth, routing, routers, and the client/server model.

LO7 Describe wireless and mobile technologies and networks.

LO8 Discuss the importance of wireless security and the techniques used.

LO9 Summarize the convergence phenomenon and its applications for business and personal use.

l e a r n i n g o u t c o m e s (cont’d.)

Chapter 6 Data Communication: Delivering Information Anywhere and Anytime

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Defining Data Communication

• Data communication – Electronic transfer of data from one location to

another– Enables an information system to deliver

information– Improves the flexibility of data collection and

transmission– Basis of virtual organizations– Provides e-collaboration

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Why Managers Need to Know About Data Communication• Separating an organization’s core functions

from the data communication systems that enable and support them is difficult

• Enhances decision makers’ efficiency and effectiveness

• Enables organizations to use e-mail and electronic file transfer to improve efficiency and productivity

• Ways data communication technologies affect the workplace

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Why Managers Need to Know About Data Communication (cont’d.)• Managers need a clear understanding of:

– The basics of data communication and networking

– The Internet, intranets, and extranets– Wired and wireless networks– Network security issues and measures– Organizational and social effects of data

communication– Globalization issues– Applications of data communication systems

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Basic Components of a Data Communication System

• Bandwidth – Amount of data that can be transferred from

one point to another in a certain time period

• Attenuation– Loss of power in a signal as it travels from the

sending device to the receiving device

• Broadband data transmission– Multiple pieces of data are sent simultaneously

to increase the transmission rate

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Basic Concepts in a Data Communication System (cont’d.)

• Narrowband – Voice-grade transmission channel capable of

transmitting a maximum of 56,000 bps, so only a limited amount of information can be transferred

• Protocols– Rules that govern data communication,

including error detection, message length, and transmission speed

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Sender and Receiver Devices

• Device can be one of the following:– “Thin client”– Smart terminal– Intelligent terminal– Netbook– Minicomputers, mainframes, and

supercomputers– Smartphones, mobile phones, MP3 players,

PDAs, game consoles

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Modems

• Modem (short for “modulator-demodulator”) – Device that connects a user to the Internet– Not required for all Internet connections

• Types– Dial-up (analog)– Digital subscriber line (DSL)– Cable

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Communication Media

• Communication media– Also called channels– Connect sender and receiver devices

• Conducted media – Provide a physical path along which signals are

transmitted – Include twisted-pair cable, coaxial cable, and

fiber optics

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Exhibit 6.1 Types of Communication Media

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Communication Media (cont’d.)

• Radiated media – Use an antenna for transmitting data through

air or water– Some media based on “line of sight”– Include broadcast radio, terrestrial microwave,

and satellite

• Types– Point-to-point– Multipoint system

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Processing Configurations

• Data communication systems can be used in several different configurations

• Over the past 60 years, three types of processing configurations have emerged: – Centralized– Decentralized– Distributed

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Centralized Processing

• Centralized processing system– Processing is done at one central computer

• Advantage – Being able to exercise tight control on system

operations and applications

• Disadvantage– Lack of responsiveness to users’ needs

• Not commonly used

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Decentralized Processing

• Decentralized processing– Each user, department, or division has its own

computer for performing processing

• Advantage – More responsive to users

• Disadvantages– Lack of coordination– High costs– Duplication of efforts

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Distributed Processing

• Distributed processing– Centralized control and decentralized operations

• Advantages– Accessing unused processing power is possible– Computer power can be added or removed– Distance and location aren’t limiting– More compatible with organizational growth– Fault tolerance – Resources can be shared to reduce costs– Reliability is improved – More responsive to user needs

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Distributed Processing (cont’d.)

• Disadvantages– More security and privacy challenges – Incompatibility between equipment– More challenging network management

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Open Systems Interconnection Model

• Seven-layer architecture for defining how data is transmitted

• Layers:– Application– Presentation– Session– Transport– Network– Data link– Physical

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Types of Networks

• Three major types of networks:– Local area networks, wide area networks, and

metropolitan area networks

• Network interface card (NIC)– Hardware component that enables computers

to communicate over a network

• Common types of local area networks:– Ethernet and token ring

• Network operating system (NOS) must be installed

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Local Area Networks

• Connects workstations and peripheral devices that are in close proximity

• Limited geographical area• Data transfer speed varies from 100 Mbps

to 10 Gbps• Used most often to share resources• Key terms:

– Ethernet and Ethernet cable

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Wide Area Networks

• Span several cities, states, or even countries

• Owned by different parties• Data transfer speed: 28.8 Kbps to 155

Mbps• Use many different communication media• Can connect to other networks

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Metropolitan Area Networks

• Communication for multiple organizations in a city and sometimes nearby cities

• Data transfer speed varies from 34 Mbps to 155 Mbps

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Exhibit 6.4 Metropolitan Area Network

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Network Topologies

• Represents a network’s physical layout• Five common topologies

– Star– Ring– Bus– Hierarchical– Mesh

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Star Topology

• Central computer and a series of nodes• Advantages

– Cable layouts are easy to modify– Centralized control makes detecting problems

easier– Nodes can be added to the network easily– Better for handling heavy but short bursts of traffic

• Disadvantages– Single point of potential failure– Increased cost due to many cables

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Ring Topology

• Each computer manages its own connectivity

• Each node is connected to two other nodes– Upstream neighbor and downstream neighbor

• Transmission in one direction• Implementations

– Token ring– Fiber Distributed Data Interface (FDDI)

• Needs less cable than star• Handles heavy short bursts well

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Bus Topology

• Connects nodes along a network segment – Ends of the cable aren’t connected– Terminator absorbs signal at each end

• A node failure has no effect on any other node

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Bus Topology (cont’d.)

• Advantages– Easy to extend– Very reliable– Wiring layout is simple and uses the least

amount of cable of any topology– Best for handling steady (even) traffic

• Disadvantages– Fault diagnosis is difficult– Bus cable can be a bottleneck when network

traffic is heavy

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Hierarchical Topology

• Combines computers with different processing strengths in different organizational levels

• Traditional mainframe networks• Controller

– Hardware and software device that controls data transfer from a computer to a peripheral device

• Multiplexer– Hardware device that allows several nodes to

share one communication channel

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Hierarchical Topology (cont’d.)

• Advantages– Network control– Lower costs

• Disadvantages– Expansion may be a problem– Traffic congestion at root and higher-level

nodes

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Mesh Topology

• Every node is connected to every other node

• Advantages– Highly reliable

• Disadvantages– Costly– Difficult to maintain– Difficult to expand

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Major Networking Concepts

• Important networking concepts– Protocols– TCP/IP– Routing– Routers– Client/server model

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Protocols

• Agreed-on methods and rules that electronic devices use to exchange information

• Deal with hardware connections• Control data transmission and file

transfers• Specify the format of message packets • Multiple protocol support is important

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Transmission Control Protocol/Internet Protocol

• Industry-standard suite of communication protocols

• Main advantage is that it enables interoperability

• Originally intended for Internet communication• Major protocols in the TCP/IP suite:

– Transmission Control Protocol (TCP)• Operates at the OSI model’s Transport layer

– Internet Protocol (IP)• Operates at the OSI model’s Network layer

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Routing

• Packet – Collection of binary digits, including message

data and control characters for formatting and transmitting

– Sent from computer to computer over a network

• Routing– Process of deciding which path data takes– Decisions made using routing table– Centralized routing– Distributed routing

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Routers

• Network connection device containing software

• Connects network systems and controls traffic flow between them

• Must use a common routing protocol• Operates at network layer• Performs the same functions as a bridge

– More sophisticated device

• Chooses the best possible path for packets• Static and dynamic routers

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Client/Server Model

• Software runs on the local computer (the client) – Communicates with the remote server to request

information or services

• Server– Remote computer on the network that provides

information or services in response to client requests

• Basic client/server communication• Advantage: scalability• Three levels of logic: presentation, application,

and data management

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Two-Tier Architecture

• Client communicates directly with the server

• Presentation logic is always on the client• Data management logic is on the server• Application logic located on either or both• Effective in small workgroups

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Exhibit 6.7 A Two-Tier Client/Server Architecture

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N-Tier Architectures

• Balance the workload between client and server • Removes application processing from both the

client and server– Places it on a middle-tier server

• Three-tier– Most common n-tier architecture

• Advantages:– Improved network performance

• Disadvantage– Network management more challenging

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Exhibit 6.8 An N-Tier Architecture

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Wireless and Mobile Networks

• Wireless network – Uses wireless instead of wired technology

• Mobile network – Network operating on a radio frequency (RF),

consisting of radio cells served by a base station

• Advantages– Mobility, flexibility, ease of installation, and low cost

• Disadvantages– Limited throughput and range, in-building

penetration problems, vulnerability to frequency noise, and security

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Wireless Technologies

• Groups– Wireless LANs– Wireless WANs

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Mobile Networks

• Three part architecture– Base stations– Mobile telephone switching offices (MTSOs)– Mobile communication devices

• Technologies– Time Division Multiple Access (TDMA)– Code Division Multiple Access (CDMA)

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Exhibit 6.11 Mobile Network Architecture

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Wireless Security

• Especially important in a wireless network• Access point (AP): part of a WLAN that

connects it to other networks• Finding WLANs is an easy task• Techniques

– SSID (Service Set Identifier)– WEP (Wired Equivalent Privacy)– EAP (Extensible Authentication Protocol)– WPA (Wi-Fi Protected Access)– WPA2 or 802.11i

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Convergence of Voice, Video, and Data

• Convergence – Integrating voice, video, and data so that multimedia

information can be used for decision making

• Convergence required network upgrades• Common applications:

– E-commerce– Entertainment– Video and computer conferencing– Consumer applications

• Telepresence: Real-life communication experience

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Summary

• Data communication systems:– Basic components– Processing configurations– Types of networks– Network topologies– Important networking concepts

• Wireless and mobile networks• Future trends in data communication:

– Convergence and telepresence

Documents

1 MIS, Chapter 5 ©2013 Course Technology, a part of Cengage Learning PROTECTING INFORMATION RESOURCES CHAPTER 5 Hossein BIDGOLI MIS