由於數位科技的進步和網路頻寬的普及，人們可以很輕易的修改、複製和散播數位多媒體內容。為了防止消費者有侵犯數位內容的行為，數位版權管理系統已發展來保護智慧財產權。但使用者往往不喜歡新系統的約束，且當此約束有影響到個人隱私時，就更難讓系統普遍的讓人接受。所以我們提供了一個新的協定，在此協定之下消費者可以匿名的購買電影。我們相信這樣一個強調消費者隱私權的系統可以更容易使系統普及。
除此之外，我們加入了匿名使用者身份辨識資訊，避免消費者藉著隱私權保護機制侵犯數位版權。在此論文中，使用者身份辨識資訊是信用卡卡號。此卡號會加密成為匿名身分辨識資訊。當數位內容提供者發現有非法的電影流傳的網路上時，可以藉著數位內容裡的身分辨識資訊追朔非法散播者。我們論文中的身分辨識資訊可以抵抗至多九個消費者的聯合平均攻擊。

In order to protect the intellectual property rights of digital content, a DRM system has been developed to prevent illegal behaviors of consumers. People are not willing to accept a new restriction that is insensitive to privacy concerns. So, we propose a new protocol which can provide anonymous buying.
Furthermore, we add the anonymous fingerprinting to prevent customers taking advantage of the privacy protection mechanisms to violate the copyright. In the thesis, fingerprinting is customer’s credit card number which is encrypted to become anonymous fingerprinting. When content providers find the illegal video distributing on the internet, they can extract the fingerprinting in the multimedia content and trace the distributors. Our fingerprinting scheme can resist average collusion attack up to 9 colluders.

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