Chapter 11
E-Commerce Security
Electronic Commerce Prentice Hall? 2006 2
Learning Objectives
1,Document the trends in computer and network security
attacks.
2,Describe the common security practices of businesses of
all sizes.
3,Understand the basic elements of EC security.
4,Explain the basic types of network security attacks.
5,Describe common mistakes that organizations make in
managing security.
6,Discuss some of the major technologies for securing EC
communications.
7,Detail some of the major technologies for securing EC
networks components.
Electronic Commerce Prentice Hall? 2006 3
The Continuing Need
for E-Commerce Security
Computer Security Institute (CSI)
Nonprofit organization located in San Francisco,
California,that is dedicated to serving and training
information,computer,and network security
professionals
Computer Emergency Response Team (CERT)
Group of three teams at Carnegie Mellon University that
monitor the incidence of cyber attacks,analyze
vulnerabilities,and provide guidance on protecting
against attacks
Electronic Commerce Prentice Hall? 2006 4
Security Is Everyone’s Business
The DHS (Department of Homeland Security)
strategy includes five national priorities:
1,A national cyberspace security response system
2,A national cyberspace security threat and vulnerability
reduction program
3,A national cyberspace security awareness and
training program
4,Securing governments’ cyberspace
5,National security and international security
cooperation
Electronic Commerce Prentice Hall? 2006 5
Security Is Everyone’s Business
Accomplishing these priorities requires
concerted effort at five levels:
– Level 1—The Home User/Small Business
– Level 2—Large Enterprises
– Level 3—Critical Sectors/Infrastructure
– Level 4—National Issues and Vulnerabilities
– Level 5—Global
Electronic Commerce Prentice Hall? 2006 6
Security Is Everyone’s Business
National Cyber Security Division (NCSD)
A division of the Department of Homeland
Security charged with implementing U.S,
cyberspace security strategy
Electronic Commerce Prentice Hall? 2006 7
Basic Security Issues
What kinds of security questions arise?
– From the user’s perspective:
How can the user be sure that the Web server is
owned and operated by a legitimate company?
How does the user know that the Web page and
form do not contain some malicious or dangerous
code or content?
How does the user know that the owner of the Web
site will not distribute the information the user
provides to some other party?
Electronic Commerce Prentice Hall? 2006 8
Basic Security Issues
What kinds of security questions arise?
– From the company’s perspective:
How does the company know the user will not
attempt to break into the Web server or alter the
pages and content at the site?
How does the company know that the user will not
try to disrupt the server so that it is not available to
others?
Electronic Commerce Prentice Hall? 2006 9
Basic Security Issues
What kinds of security questions arise?
– From both parties’ perspectives:
How do both parties know that the network
connection is free from eavesdropping by a third
party ―listening‖ on the line?
How do they know that the information sent back-
and-forth between the server and the user’s
browser has not been altered?
Electronic Commerce Prentice Hall? 2006 10
Basic Security Issues
authentication
The process by which one entity verifies that another
entity is who he,she,or it claims to be
authorization
The process that ensures that a person has the right
to access certain resources
auditing
The process of collecting information about attempts
to access particular resources,use particular
privileges,or perform other security actions
Electronic Commerce Prentice Hall? 2006 11
Exhibit 11.1 General Security Issues at
EC Sites
Electronic Commerce Prentice Hall? 2006 12
Types of Threats and Attacks
nontechnical attack
An attack that uses chicanery to trick people into
revealing sensitive information or performing
actions that compromise the security of a
network
Electronic Commerce Prentice Hall? 2006 13
Types of Threats and Attacks
Nontechnical Attacks,Social Engineering
social engineering
A type of nontechnical attack that uses social
pressures to trick computer users into compromising
computer networks to which those individuals have
access
– A multiprong approach should be used to combat
social engineering
Education and training
Policies and procedures
Penetration testing
Electronic Commerce Prentice Hall? 2006 14
Types of Threats and Attacks
technical attack
An attack perpetrated using software and systems
knowledge or expertise
common (security) vulnerabilities and exposures
(CVEs)
Publicly known computer security risks,which are
collected,listed,and shared by a board of security-
related organizations (cve.mitre.org)
National Infrastructure Protection Center (NIPC)
A joint partnership under the auspices of the FBI
between governmental and private industry; designed to
prevent and protect the nation’s infrastructure
Electronic Commerce Prentice Hall? 2006 15
Types of Threats and Attacks
denial-of-service (DoS) attack
An attack on a Web site in which an attacker uses
specialized software to send a flood of data packets
to the target computer with the aim of overloading
its resources
distributed denial-ofservice (DDoS) attack
A denial-of-service attack in which the attacker
gains illegal administrative access to as many
computers on the Internet as possible and uses the
multiple computers to send a flood of data packets
to the target computer
Electronic Commerce Prentice Hall? 2006 16
Exhibit 11.2 Using Zombies in a Distributed
Denial-of-Service Attack
Electronic Commerce Prentice Hall? 2006 17
Types of Threats and Attacks
malware
A generic term for malicious software
A number of factors have contributed to the overall
increase in malicious code,Among these factors,
the following are paramount:
– Mixing data and executable instructions
– Increasingly homogenous computing
environments
– Unprecedented connectivity
– Larger clueless user base
Electronic Commerce Prentice Hall? 2006 18
Types of Threats and Attacks
– As the number of attacks increases,the following
trends in malicious code are emerging:
Increased speed and volume of attacks
Reduced time between the discovery of a vulnerability
and the release of an attack to exploit the vulnerability
Remotely-controlled bot networks are growing
E-commerce is the most frequently targeted industry
Attacks against Web application technologies are
increasing
A large percent of Fortune 100 companies have been
compromised by worms
Electronic Commerce Prentice Hall? 2006 19
Types of Threats and Attacks
virus
A piece of software code that inserts itself into a host,
including the operating systems,in order to propagate; it
requires that its host program be run to activate it
worm
A software program that runs independently,consuming
the resources of its host in order to maintain itself,that is
capable of propagating a complete working version of itself
onto another machine
Electronic Commerce Prentice Hall? 2006 20
Managing EC Security
Common mistakes in managing security risks:
– Undervalued information
– Narrowly defined security boundaries
– Reactive security management
– Dated security management processes
– Lack of communication about security responsibilities
Electronic Commerce Prentice Hall? 2006 21
Managing EC Security
Security Risk Management
security risk management
A systematic process for determining the likelihood of
various security attacks and for identifying the actions
needed to prevent or mitigate those attacks
– Security risk management consists of three phases:
Asset identification
Risk assessment
Implementation
Electronic Commerce Prentice Hall? 2006 22
Securing EC Communications
access control
Mechanism that determines who can legitimately use
a network resource
passive tokens
Storage devices (e.g.,magnetic strips) that contain a
secret code used in a two-factor authentication
system
active tokens
Small,stand-alone electronic devices that generate
one-time passwords used in a two-factor
authentication system
Electronic Commerce Prentice Hall? 2006 23
Securing EC Communications
biometric systems
Authentication systems that identify a person by
measurement of a biological characteristic,such as
fingerprints,iris (eye) patterns,facial features,or voice
physiological biometrics
Measurements derived directly from different parts of the
body (e.g.,fingerprint,iris,hand,facial characteristics)
behavioral biometrics
Measurements derived from various actions and
indirectly from various body parts (e.g.,voice scans or
keystroke monitoring)
Electronic Commerce Prentice Hall? 2006 24
Securing EC Communications
fingerprint scanning
Measurement of the discontinuities of a person’s
fingerprint,which are then converted to a set of
numbers that are stored as a template and used to
authenticate identity
iris scanning
Measurement of the unique spots in the iris (colored
part of the eye),which are then converted to a set of
numbers that are stored as a template and used to
authenticate identity
Electronic Commerce Prentice Hall? 2006 25
Securing EC Communications
public key infrastructure (PKI)
A scheme for securing e-payments using public key
encryption and various technical components
encryption
The process of scrambling (encrypting) a message in
such a way that it is difficult,expensive,or time-
consuming for an unauthorized person to unscramble
(decrypt) it
plaintext
An unencrypted message in human-readable form
Electronic Commerce Prentice Hall? 2006 26
Securing EC Communications
ciphertext
A plaintext message after it has been encrypted
into a machine-readable form
encryption algorithm
The mathematical formula used to encrypt the
plaintext into the ciphertext,and vice versa
key
The secret code used to encrypt and decrypt a
message
Electronic Commerce Prentice Hall? 2006 27
Securing EC Communications
symmetric (private) key system
An encryption system that uses the same key to encrypt
and decrypt the message
Data Encryption Standard (DES)
The standard symmetric encryption algorithm supported
the NIST and used by U.S,government agencies until
October 2,2000
Rijndael
The new Advanced Encryption Standard used to secure
U.S,government Communications since October 2,
2000
Electronic Commerce Prentice Hall? 2006 28
Exhibit 11.4 Symmetric (Private) Key
Encryption
Electronic Commerce Prentice Hall? 2006 29
Securing EC Communications
Public (Asymmetric) Key Encryption
public key encryption
Method of encryption that uses a pair of
matched keys—a public key to encrypt a
message and a private key to decrypt it,or vice
versa
public key
Encryption code that is publicly available to
anyone
Electronic Commerce Prentice Hall? 2006 30
Securing EC Communications
Digital Signatures
digital signature
An identifying code that can be used to authenticate
the identity of the sender of a document
hash
A mathematical computation that is applied to a
message,using a private key,to encrypt the
message
Electronic Commerce Prentice Hall? 2006 31
Securing EC Communications
Digital Signatures
message digest
A summary of a message,converted into a string of
digits,after the hash has been applied
digital envelope
The combination of the encrypted original message
and the digital signature,using the recipient’s public
key
Electronic Commerce Prentice Hall? 2006 32
Exhibit 11.5 Digital Signatures
Electronic Commerce Prentice Hall? 2006 33
Securing EC Communications
digital certificate
Verification that the holder of a public or private
key is who he or she claims to be
certificate authorities (CAs)
Third parties that issue digital certificates
Electronic Commerce Prentice Hall? 2006 34
Securing EC Communications
Secure Socket Layer (SSL)
Protocol that utilizes standard certificates for
authentication and data encryption to ensure
privacy or confidentiality
Transport Layer Security (TLS)
As of 1996,another name for the SSL protocol
Electronic Commerce Prentice Hall? 2006 35
Securing EC Networks
policy of least privilege (POLP)
Policy of blocking access to network resources
unless access is required to conduct business
Electronic Commerce Prentice Hall? 2006 36
Exhibit 11.6 Layered Security
Electronic Commerce Prentice Hall? 2006 37
Securing EC Networks
The selection and operation of these
technologies should be based on certain design
concepts,including:
– Layered security
– Controlling access
– Role-specific security
– Monitoring
– Keep systems patched
– Response team
Electronic Commerce Prentice Hall? 2006 38
Securing EC Networks
firewall
A network node consisting of both hardware
and software that isolates a private network
from a public network
packet-filtering routers
Firewalls that filter data and requests moving
from the public Internet to a private network
based on the network addresses of the
computer sending or receiving the request
Electronic Commerce Prentice Hall? 2006 39
Securing EC Networks
packets
Segments of data and requests sent from one computer
to another on the Internet; consist of the Internet
addresses of the computers sending and receiving the
data,plus other identifying information that distinguish
one packet from another
packet filters
Rules that can accept or reject incoming packets
based on source and destination addresses and the
other identifying information
Electronic Commerce Prentice Hall? 2006 40
Securing EC Networks
application-level proxy
A firewall that permits requests for Web pages to move
from the public Internet to the private network
bastion gateway
A special hardware server that utilizes application-level
proxy software to limit the types of requests that can be
passed to an organization’s internal networks from the
public Internet
proxies
Special software programs that run on the gateway
server and pass repackaged packets from one network
to the other
Electronic Commerce Prentice Hall? 2006 41
Exhibit 11.7 Application Level Proxy
(Bastion Gateway Host)
Electronic Commerce Prentice Hall? 2006 42
Securing EC Networks
demilitarized zone (DMZ)
Network area that sits between an organization’s
internal network and an external network (Internet),
providing physical isolation between the two networks
that is controlled by rules enforced by a firewall.
personal firewall
A network node designed to protect an individual
user’s desktop system from the public network by
monitoring all the traffic that passes through the
computer’s network interface card.
Electronic Commerce Prentice Hall? 2006 43
Exhibit 11.8 Demilitarized Zone (DMZ)
Electronic Commerce Prentice Hall? 2006 44
Securing EC Networks
virtual private network (VPN)
A network that uses the public Internet to carry
information but remains private by using encryption to
scramble the communications,authentication to ensure
that information has not been tampered with,and
access control to verify the identity of anyone using the
network
protocol tunneling
Method used to ensure confidentiality and integrity of
data transmitted over the Internet,by encrypting data
packets,sending them in packets across the Internet,
and decrypting them at the destination address
Electronic Commerce Prentice Hall? 2006 45
Securing EC Networks
intrusion detection systems (IDSs)
A special category of software that can monitor
activity across a network or on a host computer,
watch for suspicious activity,and take
automated action based on what it sees
Electronic Commerce Prentice Hall? 2006 46
Securing EC Networks
honeynet
A way to evaluate vulnerabilities of an organization by
studying the types of attacks to which a site is
subjected using a network of systems called
honeypots
honeypots
Production systems (e.g.,firewalls,routers,Web
servers,database servers) designed to do real work
but that are watched and studied as network
intrusions occur
Electronic Commerce Prentice Hall? 2006 47
Managerial Issues
1,Have we budgeted enough for security?
2,What are the business consequences of poor
security?
3,Which e-commerce sites are vulnerable to attack?
4,What is the key to establishing strong e-commerce
security?
5,What steps should businesses follow in establishing a
security plan?
6,Should organizations be concerned with internal
security threats?
Electronic Commerce Prentice Hall? 2006 48
Summary
1,Trends in computer attacks.
2,Security is everyone’s business.
3,Basic security issues.
4,Basic types of network security attacks.
5,Managing EC security.
6,Securing EC communications.
7,Technologies for securing networks.
E-Commerce Security
Electronic Commerce Prentice Hall? 2006 2
Learning Objectives
1,Document the trends in computer and network security
attacks.
2,Describe the common security practices of businesses of
all sizes.
3,Understand the basic elements of EC security.
4,Explain the basic types of network security attacks.
5,Describe common mistakes that organizations make in
managing security.
6,Discuss some of the major technologies for securing EC
communications.
7,Detail some of the major technologies for securing EC
networks components.
Electronic Commerce Prentice Hall? 2006 3
The Continuing Need
for E-Commerce Security
Computer Security Institute (CSI)
Nonprofit organization located in San Francisco,
California,that is dedicated to serving and training
information,computer,and network security
professionals
Computer Emergency Response Team (CERT)
Group of three teams at Carnegie Mellon University that
monitor the incidence of cyber attacks,analyze
vulnerabilities,and provide guidance on protecting
against attacks
Electronic Commerce Prentice Hall? 2006 4
Security Is Everyone’s Business
The DHS (Department of Homeland Security)
strategy includes five national priorities:
1,A national cyberspace security response system
2,A national cyberspace security threat and vulnerability
reduction program
3,A national cyberspace security awareness and
training program
4,Securing governments’ cyberspace
5,National security and international security
cooperation
Electronic Commerce Prentice Hall? 2006 5
Security Is Everyone’s Business
Accomplishing these priorities requires
concerted effort at five levels:
– Level 1—The Home User/Small Business
– Level 2—Large Enterprises
– Level 3—Critical Sectors/Infrastructure
– Level 4—National Issues and Vulnerabilities
– Level 5—Global
Electronic Commerce Prentice Hall? 2006 6
Security Is Everyone’s Business
National Cyber Security Division (NCSD)
A division of the Department of Homeland
Security charged with implementing U.S,
cyberspace security strategy
Electronic Commerce Prentice Hall? 2006 7
Basic Security Issues
What kinds of security questions arise?
– From the user’s perspective:
How can the user be sure that the Web server is
owned and operated by a legitimate company?
How does the user know that the Web page and
form do not contain some malicious or dangerous
code or content?
How does the user know that the owner of the Web
site will not distribute the information the user
provides to some other party?
Electronic Commerce Prentice Hall? 2006 8
Basic Security Issues
What kinds of security questions arise?
– From the company’s perspective:
How does the company know the user will not
attempt to break into the Web server or alter the
pages and content at the site?
How does the company know that the user will not
try to disrupt the server so that it is not available to
others?
Electronic Commerce Prentice Hall? 2006 9
Basic Security Issues
What kinds of security questions arise?
– From both parties’ perspectives:
How do both parties know that the network
connection is free from eavesdropping by a third
party ―listening‖ on the line?
How do they know that the information sent back-
and-forth between the server and the user’s
browser has not been altered?
Electronic Commerce Prentice Hall? 2006 10
Basic Security Issues
authentication
The process by which one entity verifies that another
entity is who he,she,or it claims to be
authorization
The process that ensures that a person has the right
to access certain resources
auditing
The process of collecting information about attempts
to access particular resources,use particular
privileges,or perform other security actions
Electronic Commerce Prentice Hall? 2006 11
Exhibit 11.1 General Security Issues at
EC Sites
Electronic Commerce Prentice Hall? 2006 12
Types of Threats and Attacks
nontechnical attack
An attack that uses chicanery to trick people into
revealing sensitive information or performing
actions that compromise the security of a
network
Electronic Commerce Prentice Hall? 2006 13
Types of Threats and Attacks
Nontechnical Attacks,Social Engineering
social engineering
A type of nontechnical attack that uses social
pressures to trick computer users into compromising
computer networks to which those individuals have
access
– A multiprong approach should be used to combat
social engineering
Education and training
Policies and procedures
Penetration testing
Electronic Commerce Prentice Hall? 2006 14
Types of Threats and Attacks
technical attack
An attack perpetrated using software and systems
knowledge or expertise
common (security) vulnerabilities and exposures
(CVEs)
Publicly known computer security risks,which are
collected,listed,and shared by a board of security-
related organizations (cve.mitre.org)
National Infrastructure Protection Center (NIPC)
A joint partnership under the auspices of the FBI
between governmental and private industry; designed to
prevent and protect the nation’s infrastructure
Electronic Commerce Prentice Hall? 2006 15
Types of Threats and Attacks
denial-of-service (DoS) attack
An attack on a Web site in which an attacker uses
specialized software to send a flood of data packets
to the target computer with the aim of overloading
its resources
distributed denial-ofservice (DDoS) attack
A denial-of-service attack in which the attacker
gains illegal administrative access to as many
computers on the Internet as possible and uses the
multiple computers to send a flood of data packets
to the target computer
Electronic Commerce Prentice Hall? 2006 16
Exhibit 11.2 Using Zombies in a Distributed
Denial-of-Service Attack
Electronic Commerce Prentice Hall? 2006 17
Types of Threats and Attacks
malware
A generic term for malicious software
A number of factors have contributed to the overall
increase in malicious code,Among these factors,
the following are paramount:
– Mixing data and executable instructions
– Increasingly homogenous computing
environments
– Unprecedented connectivity
– Larger clueless user base
Electronic Commerce Prentice Hall? 2006 18
Types of Threats and Attacks
– As the number of attacks increases,the following
trends in malicious code are emerging:
Increased speed and volume of attacks
Reduced time between the discovery of a vulnerability
and the release of an attack to exploit the vulnerability
Remotely-controlled bot networks are growing
E-commerce is the most frequently targeted industry
Attacks against Web application technologies are
increasing
A large percent of Fortune 100 companies have been
compromised by worms
Electronic Commerce Prentice Hall? 2006 19
Types of Threats and Attacks
virus
A piece of software code that inserts itself into a host,
including the operating systems,in order to propagate; it
requires that its host program be run to activate it
worm
A software program that runs independently,consuming
the resources of its host in order to maintain itself,that is
capable of propagating a complete working version of itself
onto another machine
Electronic Commerce Prentice Hall? 2006 20
Managing EC Security
Common mistakes in managing security risks:
– Undervalued information
– Narrowly defined security boundaries
– Reactive security management
– Dated security management processes
– Lack of communication about security responsibilities
Electronic Commerce Prentice Hall? 2006 21
Managing EC Security
Security Risk Management
security risk management
A systematic process for determining the likelihood of
various security attacks and for identifying the actions
needed to prevent or mitigate those attacks
– Security risk management consists of three phases:
Asset identification
Risk assessment
Implementation
Electronic Commerce Prentice Hall? 2006 22
Securing EC Communications
access control
Mechanism that determines who can legitimately use
a network resource
passive tokens
Storage devices (e.g.,magnetic strips) that contain a
secret code used in a two-factor authentication
system
active tokens
Small,stand-alone electronic devices that generate
one-time passwords used in a two-factor
authentication system
Electronic Commerce Prentice Hall? 2006 23
Securing EC Communications
biometric systems
Authentication systems that identify a person by
measurement of a biological characteristic,such as
fingerprints,iris (eye) patterns,facial features,or voice
physiological biometrics
Measurements derived directly from different parts of the
body (e.g.,fingerprint,iris,hand,facial characteristics)
behavioral biometrics
Measurements derived from various actions and
indirectly from various body parts (e.g.,voice scans or
keystroke monitoring)
Electronic Commerce Prentice Hall? 2006 24
Securing EC Communications
fingerprint scanning
Measurement of the discontinuities of a person’s
fingerprint,which are then converted to a set of
numbers that are stored as a template and used to
authenticate identity
iris scanning
Measurement of the unique spots in the iris (colored
part of the eye),which are then converted to a set of
numbers that are stored as a template and used to
authenticate identity
Electronic Commerce Prentice Hall? 2006 25
Securing EC Communications
public key infrastructure (PKI)
A scheme for securing e-payments using public key
encryption and various technical components
encryption
The process of scrambling (encrypting) a message in
such a way that it is difficult,expensive,or time-
consuming for an unauthorized person to unscramble
(decrypt) it
plaintext
An unencrypted message in human-readable form
Electronic Commerce Prentice Hall? 2006 26
Securing EC Communications
ciphertext
A plaintext message after it has been encrypted
into a machine-readable form
encryption algorithm
The mathematical formula used to encrypt the
plaintext into the ciphertext,and vice versa
key
The secret code used to encrypt and decrypt a
message
Electronic Commerce Prentice Hall? 2006 27
Securing EC Communications
symmetric (private) key system
An encryption system that uses the same key to encrypt
and decrypt the message
Data Encryption Standard (DES)
The standard symmetric encryption algorithm supported
the NIST and used by U.S,government agencies until
October 2,2000
Rijndael
The new Advanced Encryption Standard used to secure
U.S,government Communications since October 2,
2000
Electronic Commerce Prentice Hall? 2006 28
Exhibit 11.4 Symmetric (Private) Key
Encryption
Electronic Commerce Prentice Hall? 2006 29
Securing EC Communications
Public (Asymmetric) Key Encryption
public key encryption
Method of encryption that uses a pair of
matched keys—a public key to encrypt a
message and a private key to decrypt it,or vice
versa
public key
Encryption code that is publicly available to
anyone
Electronic Commerce Prentice Hall? 2006 30
Securing EC Communications
Digital Signatures
digital signature
An identifying code that can be used to authenticate
the identity of the sender of a document
hash
A mathematical computation that is applied to a
message,using a private key,to encrypt the
message
Electronic Commerce Prentice Hall? 2006 31
Securing EC Communications
Digital Signatures
message digest
A summary of a message,converted into a string of
digits,after the hash has been applied
digital envelope
The combination of the encrypted original message
and the digital signature,using the recipient’s public
key
Electronic Commerce Prentice Hall? 2006 32
Exhibit 11.5 Digital Signatures
Electronic Commerce Prentice Hall? 2006 33
Securing EC Communications
digital certificate
Verification that the holder of a public or private
key is who he or she claims to be
certificate authorities (CAs)
Third parties that issue digital certificates
Electronic Commerce Prentice Hall? 2006 34
Securing EC Communications
Secure Socket Layer (SSL)
Protocol that utilizes standard certificates for
authentication and data encryption to ensure
privacy or confidentiality
Transport Layer Security (TLS)
As of 1996,another name for the SSL protocol
Electronic Commerce Prentice Hall? 2006 35
Securing EC Networks
policy of least privilege (POLP)
Policy of blocking access to network resources
unless access is required to conduct business
Electronic Commerce Prentice Hall? 2006 36
Exhibit 11.6 Layered Security
Electronic Commerce Prentice Hall? 2006 37
Securing EC Networks
The selection and operation of these
technologies should be based on certain design
concepts,including:
– Layered security
– Controlling access
– Role-specific security
– Monitoring
– Keep systems patched
– Response team
Electronic Commerce Prentice Hall? 2006 38
Securing EC Networks
firewall
A network node consisting of both hardware
and software that isolates a private network
from a public network
packet-filtering routers
Firewalls that filter data and requests moving
from the public Internet to a private network
based on the network addresses of the
computer sending or receiving the request
Electronic Commerce Prentice Hall? 2006 39
Securing EC Networks
packets
Segments of data and requests sent from one computer
to another on the Internet; consist of the Internet
addresses of the computers sending and receiving the
data,plus other identifying information that distinguish
one packet from another
packet filters
Rules that can accept or reject incoming packets
based on source and destination addresses and the
other identifying information
Electronic Commerce Prentice Hall? 2006 40
Securing EC Networks
application-level proxy
A firewall that permits requests for Web pages to move
from the public Internet to the private network
bastion gateway
A special hardware server that utilizes application-level
proxy software to limit the types of requests that can be
passed to an organization’s internal networks from the
public Internet
proxies
Special software programs that run on the gateway
server and pass repackaged packets from one network
to the other
Electronic Commerce Prentice Hall? 2006 41
Exhibit 11.7 Application Level Proxy
(Bastion Gateway Host)
Electronic Commerce Prentice Hall? 2006 42
Securing EC Networks
demilitarized zone (DMZ)
Network area that sits between an organization’s
internal network and an external network (Internet),
providing physical isolation between the two networks
that is controlled by rules enforced by a firewall.
personal firewall
A network node designed to protect an individual
user’s desktop system from the public network by
monitoring all the traffic that passes through the
computer’s network interface card.
Electronic Commerce Prentice Hall? 2006 43
Exhibit 11.8 Demilitarized Zone (DMZ)
Electronic Commerce Prentice Hall? 2006 44
Securing EC Networks
virtual private network (VPN)
A network that uses the public Internet to carry
information but remains private by using encryption to
scramble the communications,authentication to ensure
that information has not been tampered with,and
access control to verify the identity of anyone using the
network
protocol tunneling
Method used to ensure confidentiality and integrity of
data transmitted over the Internet,by encrypting data
packets,sending them in packets across the Internet,
and decrypting them at the destination address
Electronic Commerce Prentice Hall? 2006 45
Securing EC Networks
intrusion detection systems (IDSs)
A special category of software that can monitor
activity across a network or on a host computer,
watch for suspicious activity,and take
automated action based on what it sees
Electronic Commerce Prentice Hall? 2006 46
Securing EC Networks
honeynet
A way to evaluate vulnerabilities of an organization by
studying the types of attacks to which a site is
subjected using a network of systems called
honeypots
honeypots
Production systems (e.g.,firewalls,routers,Web
servers,database servers) designed to do real work
but that are watched and studied as network
intrusions occur
Electronic Commerce Prentice Hall? 2006 47
Managerial Issues
1,Have we budgeted enough for security?
2,What are the business consequences of poor
security?
3,Which e-commerce sites are vulnerable to attack?
4,What is the key to establishing strong e-commerce
security?
5,What steps should businesses follow in establishing a
security plan?
6,Should organizations be concerned with internal
security threats?
Electronic Commerce Prentice Hall? 2006 48
Summary
1,Trends in computer attacks.
2,Security is everyone’s business.
3,Basic security issues.
4,Basic types of network security attacks.
5,Managing EC security.
6,Securing EC communications.
7,Technologies for securing networks.
