電子商務

1. Chapter 12 Electronic Commerce Systems Accounting Information Systems, 5 th edition James A. Hall (Revised by Jiin-Feng Chen, National Chengchi University for classroom use) COPYRIGHT © 2007 Thomson South-Western, a part of The Thomson Corporation. Thomson, the Star logo, and South-Western are trademarks used herein under license

8. SSL Architecture Two layers of protocols

9. Secure Electronic Transaction (SET) 憑證中心

11. The OSI Protocol Data Manipulation Tasks Data Communications Tasks Communications Channel NODE 1 NODE 2 HARD WARE HARD WARE Layer 1 Physical Layer 2 Data Link Layer 3 Network Layer 4 Transport Layer 5 Session Layer 6 Presentation Layer 7 Application SOFT WARE HARD WARE Layer 1 Physical Layer 2 Data Link Layer 3 Network Layer 4 Transport Layer 5 Session Layer 6 Presentation Layer 7 Application SOFT WARE HARD WARE

14. Comparing HTML and XML

18. Dynamic Virtual Organization Perhaps the greatest potential benefit to be derived from e-commerce is the firm’s ability to forge dynamic business alliances with other organizations to fill unique market niches as the opportunities arise.

23. DOS Attack Sender Receiver Step 1: SYN messages Step 2: SYN/ACK Step 3: ACK packet code In a DOS Attack, the sender sends hundreds of messages, receives the SYN/ACK packet, but does not response with an ACK packet. This leaves the receiver with clogged transmission ports, and legitimate messages cannot be received.

25. Public and Private Key Encryption 公開及秘密金鑰加密 Public Key is used for encoding messages. Message B Message C Message D Multiple people may have the public key (e.g., subordinates). Private Key is used for decoding messages. Typically one person or a small number of people have the private key (e.g., a supervisor). Message A Ciphertext Ciphertext Ciphertext Ciphertext Message A Message D Message C Message B

27. Text Message Compute Digest of Message Digest Encrypt Using Sender’s Private Key Digital Signature Digital Signature Encrypt Using Receiver’s Public Key Encrypted Message with Digital Signature Attached Decrypt Using Receiver’s Private Key Digital Signature Text Message Decrypt Using Sender’s Public Key Compute Digest of Message Digest Digest Compare Digital Signature 數位簽章 Sender’s Location Receiver's Location

38. LAN LAN Bridge Gateway Gateway LAN WAN WAN 環狀網路 星狀網路 匯流排網路

40. POS POS POS POS POS Topeka St. Louis Kansas City Dallas Tulsa Star Network 主電腦 Local Data Local Data Local Data Local Data Central Data

49. POLLING METHOD OF CONTROLLING DATA COLLISIONS MASTER Locked Locked Locked Polling Signal Data Transmission One Site, the “master,” polls the other “slave” sites to determine if they have data to transmit. If a slave responds in the affirmative, the master site locks the network while the data are transmitted. Allows priorities to be set for data communications across the network SLAVE SLAVE SLAVE SLAVE WAN

54. EDI System Purchases System Company A’s mailbox Company B’s mailbox Sales Order System Application Software Application Software Direct Connection VAN Company A Company B EDI Translation Software EDI Translation Software Communications Software Communications Software Other Mailbox Other Mailbox