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E-Commerce Security
Notes based on Laudon&Laudon.
Prentice Hall, 2002
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Learning Objectives
Document the rapid rise in computer and
network security attacks
Understand the factors contributing to the
rise in EC security breaches
Explain the basic types of network security
attacks
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Learning Objectives (cont.)
Discuss the major steps in developing a
security risk management system
Describe the major types of attacks
against EC systems
Discuss some of the major technologies
for securing EC
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Bringing Down an EC Site:
Mere Child’s Play
Distributed Denial of Service (DDoS)
attacks can inundate a site with so many
requests that legitimate traffic is virtually
halted
Attacker used software to send a flood of data
packets to the target computer(s) with the aim
of overloading its resources
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Figure 13-1
Using Zombies in a Distributed Denial of Service Attack
Source: Scambray et al. (2000)
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Bringing Down an EC Site:
Mere Child’s Play (cont.)
Distributed Denial of Service (DDoS) attacks
Zombie—machine on which the DDoS software is
loaded, unknown to the owner
Home computers with cable modems or DSL
service that are left on all the time
Business Web servers located outside the
firewall
Availability of free tools and scripts make it easy
to mount a DDOS attack
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Figure 13-2
Attack Sophistication vs. Intruder Technical Knowledge
Source: Special permission to reproduce the CERT ©/CC graphic © 2000 by Carnegie Melon University, in Electronic
Commerce 2002 in Allen et al. (2000).
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The Need for Security
Data from Computer Security Institute and
FBI indicate:
Cyber attacks are on the increase
Internet connections are increasingly a point of
attack
The variety of attacks is on the rise
The reporting of serious crimes to law
enforcement has declined
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Table 13-2
Incidents and Vulnerabilities Reported to CERT
Figures from Computer Emergency
Response Team (CERT)
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Why Now?
Security systems are only as strong as
their weakest points
Security and ease of use (or
implementation) are antithetical to one
another
Security takes a back seat to market
pressures
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Why Now? (cont.)
Security of an EC site depends on the
security of the Internet as a whole
Security vulnerabilities are increasing
faster than they can be combated
Security compromised by common
applications
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Basic Security Issues
Issues at a simple marketing site:
User’s perspective
Company’s perspective
Is Web server owned
and operated by
legitimate company?
Web page and form
contain some malicious
code content?
Will Web server
distribute the user’s
information to another
party?
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Will the user attempt
to break into the Web
server or alter the
site?
Will the user try to
disrupt the server so it
isn’t available to
others?
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Basic Security Issues (cont.)
Issues at a simple marketing site:
User and company perspective
Is network connection free from
eavesdropping?
Has information sent back and forth
between server and browser been altered?
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Basic Security Issues (cont.)
Major security issues in EC
Authentication
Authorization
Auditing
Confidentiality or privacy
Integrity
Availability
Non-repudiation
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Security Risk Management
Required to determine
security needs
Definitions involved in
risk management
4 phases of risk
management
Assessment
Planning
Implementation
Monitoring
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Assets—anything of
value worth
securing
Threat—eventuality
representing danger
to an asset
Vulnerability—
weakness in a
safeguard
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Security Risk Management (cont.)
Assessment phase—evaluation of assets,
threats, vulnerabilities
Determine organizational objectives
Inventory assets
Delineate threats
Identify vulnerabilities
Quantify the value of each risk
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Table 13-3
Security Risks for EC & Other Internet Sites
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Security Risk Management (cont.)
Planning phase of risk management—
arrive at a set of security policies
Define specific policies
Establish processes for audit and review
Establish an incident response team and
contingency plan
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Security Risk Management (cont.)
Implementation phase of risk
management—choose particular
technologies to deal with high priority
threats
Monitoring phase of risk management—
ongoing processes used to determine
which measures are successful,
unsuccessful and need modification
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Types of Threats and Attacks
Nontechnical vs. technical attacks
Steps in a hacker’s attack
Discover key elements of network
Scan for vulnerabilities
Hack in and gain administrator privileges
Disable auditing & traces from log files
Steal files, modify data, steal source code, etc.
Install back doors, etc to permit undetectable
reentry
Return at will to do more damage
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Types of Threats and Attacks (cont.)
The players
Hackers
Crackers
Script kiddies
Systems and software bugs and
misconfigurations
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Types of Threats and Attacks (cont.)
Denial-of-service (DoS) attacks
IP fragmentation
(teardrop, bonk,
boink, nestea, and
others)
DNS spoofing
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Ping of death
Smurf attack
SYNFlood
Buffer overflows
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Types of Threats and Attacks (cont.)
Input validation attacks
Intercepted transmissions
Malicious code
Viruses
Worms
Macro viruses and macro worms
Trojan horses
Malicious mobile code
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Security Technologies
Tools Available to Achieve Site Security
Encryption
Network Security Protocols
Virtual Private Networks and Tunneling
Firewalls and Proxy Systems
Host security tools
Policies and Management: Access control,
authentication, monitoring and intrusion
detection.
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Figure 14-2
Private Key Encryption
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Public Key Encryption
Size of key
Speed of Key
RSA algorithm
Rijndael algorithm
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Security for E-Payments (cont.)
Digital Signatures: authenticity and nondenial
Analogous to handwritten signature
Based on public keys
Used to:
Authenticate the identity of the sender of a
message or document
Ensure the original content of the electronic
message or document is unchanged
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Security for E-Payments (cont.)
Digital Signatures: authenticity and
nondenial (cont.)
Benefits:
Portable
Cannot be easily repudiated or imitated
Can be time stamped
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Figure 14-4
Digital Signatures
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Security for E-Payments (cont.)
Digital certificates
Identifying the
holder of a public
key (Key-Exchange)
Issued by a trusted
certificate authority
(CA)
Name : “Richard”
key-Exchange Key :
Signature Key :
Serial # : 29483756
Other Data : 10236283025273
Expires : 6/18/04
Signed : CA’s Signature
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Security for E-Payments (cont.)
Secure socket layer/transport layer security
Secure socket layer (SLL)—handle on Web browser,
utilizing CAs and data encryption
Encryption
Digital certificates
Digital signatures
In 1996 SSL was standardized and named transport
layer security (TSL)
Operates at TCP/IP layer (base layer for Internet)
IPSec—secure version of IP protocol
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SSL
Secure Socket Layer (SSL)
SSL protocol may use a
certificate, but there is no
payment gateway. Merchants
need to receive ordering
information and credit card
information (capturing process
initiated by merchants)
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Security Technologies
Firewalls and access control
Firewall—network node that isolates private
network from public network
Packet-filtering routers
Application-level proxies
Screened host firewall
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Figure 13-6
Application-Level Proxy (Bastion Gateway Host)
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Figure 13-7
Screened Host Firewall
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Figure 13-8
Screened Subnet Firewall (with DMZ)
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Security Technologies (cont.)
Virtual private networks (VPNs)—use
public Internet to carry information but
remains private
Encryption—scramble communications
Authentication—ensure information remains
untampered with and comes from legitimate
source
Access control—verify identity of anyone using
network
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Security Technologies (cont.)
Protocol tunneling—ensure confidentiality
and integrity of data transmitted
Point-to-point tunneling (PTP)
Layer 2 tunneling protocol (L2PT)
Intrusion Detection Systems (IDS)
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Managerial Issues
Recognize the business consequences of
poor security
Security through obscurity doesn't work
It’s the business that counts, not the
technology
Security is an on-going, closed-loop process
Even for EC sites, internal breaches are more
prevalent than external breaches
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