A Study on Secure and Anonymous Electronic Commerce Schemes

[[abstract]]近年來，隨著網路技術的普及，越來越多傳統交易透過網路的方式進行運作。然而，網路世界並非面對面進行溝通，因此「身分驗證」成為電子商務中重要的議題。有鑑於此，本論文結合指紋辨識功能，提出一種有效率的生物測定之遠端使用者驗證系統，提供電子商務在身分驗證的應用。 在眾多現行的電子商務類型之中，「電子拍賣」扮演了重要角色。目前電子拍賣可大致分為三類：英式拍賣、荷式拍賣以及封閉式拍賣。然而，透過網路公開投競標，易產生許多隱私洩漏的疑慮。因此，如何提供拍賣者匿名性以及拍賣隱私性，則成為電子拍賣上的重要議題。基於上述原因，本論文首先提出一種植基於離散對數困難度的實用英式拍賣機制；為了提供更多元的電子拍賣應用，本論文結合零知識證明理論，以確保拍賣者擁有更完整的安全性與匿名性，提出一種安全性與強匿名性的電子拍賣機制，藉以提供更實用的電子拍賣應用與環境。除此之外，此電子拍賣機制也將更適用於現今任何型態的電子拍賣中，如：英式拍賣、荷式拍賣、以及封閉式拍賣。 在電子付款機制盛行的現今，結合各種電子付款的研究也陸續提出，例如：結合電子現金（E-Cash）以及網路現金轉帳等。然而，上述皆只確保拍賣單方可獲得金額，並未能真正達成「公平交易」的需求。此外，在現今眾多的電子拍賣相關研究中，針對公平交易的需求，也尚未提出較合適的解決方法。基於此缺失，本論文提出一種具有公平交易特性的嶄新電子拍賣機制。此機制達成兩個目標：(1) 使用數位簽章技術，提供拍賣的安全性，並確保未得標者的拍賣資訊不被洩漏；(2) 結合公平交易機制，設計並使用電子代幣（E-Token）的 概念，提昇拍賣雙方在交易前的信心，並確保雙方皆能公平的完成交易。最後，本論文更針對拍賣貨品，進一步將其分為實體貨品與數位貨品兩類做討論，以便提供在現實世界中之電子拍賣機制更為多元的應用。[[abstract]]Recently, with the popularity of the Internet, electronic commerce (e-commerce) covers all transactions conducted through electronic means. However, the communication of network is not face to face, hence "remote user authentication" has become an important part of e-commerce. Therefore, in this thesis, we proposed an efficient biometrics remote user authentication scheme that utilizes fingerprint identification function. The "electronic auction" (e-auction) plays an important role in e-commerce. Generally, e-auction can be categorized into three types: English auction, Dutch auction and sealed-bid auction. However, bidding through network brings a lot of security problems. Hence, how to provide anonymous and bidding privacy is an important issue. For this reason, a practical e-English auction based on the discrete logarithms is proposed. Moreover, in order to provide more practical e-auction scheme, an e-auction scheme with strong anonymity and bidding privacy is also proposed in this thesis. We combines with zero knowledge proof to provide a secure auction environment for bidders. This scheme also applies to any type of existing e-auction scheme, such as: English auction, Dutch auction, sealed-bid auction. Many e-auction schemes based on various kinds of e-payment schemes are commonly used, for example: e-cash, the network cash transfer accounts and so on. However, the schemes only ensure that the sellers could get the money, which is not "fair-exchange" actually. So far, there are no appropriate methods to solve the fairness requirements in e-auction yet. For this reason, this thesis proposes a novel fair-exchange electronic auction scheme. We divided the novel scheme into two subgoals: (1) adopting digital signature, so that the anonymity and auction behavior of bidder can be guaranteed, (2) using the concept of e-token to promote the confidence of both parties. So that "fair-exchange" can be achieved. In order to implement this scheme in the real world, this thesis will separately discuss the scheme in entity and digital goods.[[note]]博