離線電子錢包系統應用於智慧型行動裝置

Off-line E-wallet System applied in Intelligent Mobile Device

江承軒(Cheng-Syuan Jiang)

指導教授 ： 楊伏夷

朝陽科技大學/資訊學院/資訊工程系/碩士(2011年)

摘要

隨著網路科技的快速發展，電子商務的服務也逐漸出現在日常生活中，帶給人們許多的便利性。在電子商務中，其中電子現金系統(或稱電子錢包系統)扮演著相當重要的角色，在交易時使用者不用攜帶大量的現金在身上，甚至可以透過網際網路就可以完成買賣交易，而且每筆電子現金有都完整的交易紀錄，提供使用者隨時查詢自己的消費紀錄。線上電子錢包系統在交易時需要即時透過銀行驗證其有效性。相較於線上電子錢包系統，離線電子錢包系統更加實用和有效率，在交易時不需要透過銀行來付款，但是離線電子錢包容易造成重複消費的問題，因此在設計上需要使用較多複雜的運算才能防止重複消費的問題發生。
本篇論文使用相關的密碼技術，設計一個具備公平和安全的電子現金系統，消費者使用電子現金消費時，能確保自身的安全性和匿名性。在我們設計的系統中，使用代理人的技術來達到匿名的特性以及防止重複消費的問題產生，假設銀行或任何人收到一筆電子現金，無法回推出這筆電子現金跟消費者之間的關聯性，因此有達到匿名的特性。在付款時，消費者會請求代理人簽發電子現金來付款，由於電子現金在產生時包括店家身份和時間等資訊，所以消費者無法重複消費這筆電子現金。
在執行效率上，我們的系統使用少量的模指數、模乘法以及單向雜湊函數來計算，透過實驗數據來證明我們的系統可以有效的應用在現實生活的智慧型行動裝置上。

關鍵字

重複消費 ； 代理人 ； 電子錢包系統 ； 智慧型行動裝置

並列摘要

With Internet technology rapidly flourishing, e-commerce services have progressively emerged in daily life and brought convenience to the people. Electronic cash systems (or electronic wallet systems) play an important role in e-commerce, which enables users to not have to carry large amounts of cash while making transactions, or enables them to even complete transactions on the Internet. Additionally, each entry of electronic cash is recorded thoroughly, allowing users to check transaction records at any time. On-line electronic wallet systems require a prompt validation from banks while transactions take place. Compared to on-line electronic wallet systems, an off-line electronic wallet system is more practical and efficient, and payment does not require going through banks. However, an off-line wallet system tends to cause double-spending, and thus a more complex calculation design is essential to prevent the problem.
This study employed related cryptographic techniques to design a fair and safe electronic cash system, ensuring the safety and anonymity of consumers to purchase by using electronic cash. The designed system employed agent techniques to achieve anonymity and prevent double-spending. When banks or anyone receives an electronic cash entry, an untraceable record enables the link between the entry and the consumer to remain anonymous. When consumers pay bills, they request the agent to issue electronic cash. Because purchase information, such as store name and time of purchase, are provided on the electronic cash entry, the consumer would not make double-spending.
In terms of executive efficiency, our system used a minimal amount of modular exponentiations, modular multiplications, and the one-way hash function as algorithms to prove that our system can be effectively and practically applied to intelligent mobile devices via empirical statistics.

並列關鍵字

intelligent mobile devices ； electronic wallet system ； agent ； double-spending

參考文獻

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