Chapter 18:
Doing Business on the Internet
Business Data Communications, 4e
Security: The Key to E-Commerce
Communications
Encryption
Privacy
payment systems
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SSL & TLS
Secure Socket Layer
Transport Layer Security
Protocols that sit between the underlying transport
protocol (TCP) and the application
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Secure Socket Layer (SSL)
Originated by Netscape
TLS has been developed by a working group of the
IETF, and is essentially SSLv3.1
Provides security at the “socket” level, just above
the basic TCP/IP service
Can provide security for a variety of Internet
services, not just the WWW
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SSL Implementation
 Focused on the initialization/handshaking to set up a secure
channel
 Client specifies encryption method and provides challenge text
 Server authenticates with public key certificate
 Client send master key, encrypted with server key
 Server returns an encrypted master key
 Digital signatures used in initialization are based on RSA;
after initialization, single key encryption systems like DES
can be used
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Characteristics of
On-Line Payment Systems
Transaction types
Means of settlement
Operational characteristics
Privacy and security
Who takes risks
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Secure Electronic Transactions
SET is a payment protocol supporting the use of
bank/credit cards for transactions
Supported by MasterCard, Visa, and many
companies selling goods and services online
SET is an open industry standard, using RSA publickey and DES single-key encryption
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SET Participants & Interactions
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Ideal Components of
Electronic Cash
Independent of physical location
Security
Privacy
Off-line payment
No need for third-party vendor
Transferability to other users
Divisibility
“Making change”Business Data Communications, 4e
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E-Cash
Created by David Chaum in Amsterdam in 1990
Maintains the anonymity of cash transactions
Users maintain an account with a participating
financial institution, and also have a “wallet” on
their computer’s hard drive
Digital coins, or tokens, are stored in the wallet
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Electronic Commerce Infrastructure
Intrabusiness
Intranet based
Supports internal transactions and transfers
Business-to-Business (BTB or B2B)
Extranet based
Business-to-Consumer (BTC or B2C)
Internet based
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Importance of BTB Commerce
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Firewalls
Used to provide security for computers inside of a
given network
All traffic to/from network passes through firewall
Only authorized traffic is allowed through
Firewall itself is a secure system
Firewall performs authentication on users
Firewall may encrypt transmissions
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Free Trade Zones (FTZ)
 Area where communication and transactions occur between
trusted parties
 Isolated from both the external environment and the
enterprise’s internet network
 Supported by firewalls on both ends
 Inside the FTZ, all communications can be in clear mode
without any encryption
 Necessary because logical boundaries between BTB and IB
are becoming fuzzy.
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