文档介绍：merce
SET is the answer, but you have to phrase the
question very carefully
Electronic Payments
An electronic payment system needs to be
• Widely recognised
• Hard to fake
• Hold its value
• Convenient to use
• Anonymous/not anonymous
Convenience is the most important point
Cheques
Merchant doesn’t know whether the cheque is valid until
it’s cleared
Cheques (ctd)
Consumer can’t detect fraud until the statement arrives
Cost of processing errors vastly outweighs the cost of
normal actions
Credit Cards
Authentication is online
Settlement is usually offline (batch processed at end of
day)
Credit Cards (ctd)
Consumer can’t detect fraud until the statement arrives
Cost of processing errors vastly outweighs the cost of
normal actions
Merchant carries the risk of fraud in card not present
transactions
Consumer liability is limited to $50
Far more merchant fraud than consumer fraud
Credit panies assume liability for their merchants;
banks with cheques don’t
Transactions on the
Transactions are fairly conventional card not present
transactions and follow the precedent set by phone
orders
Online nature provides instant verification
Biggest problems are authentication and confidentiality
General Model of Transactions
Virtually payment systems consist of some variant
of this
Everyone wants to be the middleman
Retail vs Business-to-merce
merce
• Small dollar amounts
• Stranger-to-stranger transactions
Business-to-merce
• Large dollar amounts
• Based on trust relationships
• Banks play a direct role — they guarantee the transaction
– You can’t disintermediate the banks
Business-to-merce is where the money is
• For retail transactions, you can’t beat a credit card over SSL
Business customers will buy to reduce current costs
Payment Systems
Book entry systems
• Credit cards over SSL
• Encrypted credit cards (Cybercash)
• Virtual credit cards (First Virtual)
• e-cheques (Netcash)
• Mondex/SET