隨著網路發展，數位商品及網路拍賣興起，網路購物的小額付款(Micropayment)有愈趨發展的潛力，也帶動個人間交易的付款行為及對小額付款機制之需求。而目前電子商務以信用卡付款機制為主要付款媒介，但該方法商家必需負擔給信用卡銀行的手續費用，客戶之信用卡機密資料亦有外流的風險，因此該方式並不適用於小額付款。 本篇的研究目的為因應小額付款之特性，設計以Ecash為付款媒介之交易流程協定，實作代理人技術建置小額付款系統，並支援P2P(Peer-to-Peer)之個人間交易。系統設計為多重代理人付款系統(MAPS, Multi-Agent Payment System)，為因應P2P之個人間交易，使用者有賣方及消費者兩種身分，本系統分別以收款代理人及付款代理人彈性支援收付款行為；雙方代理人並能以代理人溝通語言(ACL, Agent Communication Language)代理賣方及消費者進行溝通及處理收付款。於安全及效率方面，亦考量個人間交易特性，一般電腦之軟硬體及網路狀況不一；因此，本系統設計以效能較高、計算成本較低之環境金鑰(Environmental Key)對稱式加密及雜湊運算支援交易付款之安全性。環境金鑰之特性為能免去對稱式金鑰於傳輸及保管的安全問題，而保留對稱式金鑰的運算效能，能有效支援付款加密。此外，動態代理人之設計亦減少於交易流程協定中之網路傳輸。而在個人間交易之匿名性方面，本研究則以Ecash之盲簽章設計支援交易匿名性，提供個人之交易隱私。 Based on the development of digital contents like music services, Internet publishing, on-line game and on-line auction, there is demand for the micropayment models and mechanisms in the micropayment markets. Nowadays, credit card is the general payment tool, but merchant has to pay the procedure charges to the credit card banks with the micro profits to the credit card banks. Besides, the confidential data of customers such as credit card numbers might be put at risk if the database is stolen by malicious hackers. Therefore, the credit card is not suitable for micropayment. This thesis aimed at designing multi-agent based micropayment system with Ecash mechanism and supporting P2P (Peer-to-Peer) inter-person transaction for micropayment. The system proposed in this thesis is MAPS (Multi-Agent Payment System), which designs the payment agent and the register agent delegating the customer and the merchant respectively to support the micropayment process between peers, and the payment agent communicates with register agent in Agent Communication Language. In terms of process efficiency and security, due to the differences of computer and Internet situations between peers, MAPS adopts environmental key generation which facilitates the efficiency of encryption and the hash function to support transaction security. Environmental key generation is the symmetric encryption technology, and maintains the efficiency of symmetric encryption technology without considering the security of key safekeeping or key transmission. Further more, the design of mobile agent reduces times of message transmission over the Internet, and the blind signature used in Ecash mechanism supports the anonymity in transaction.
