企業數位權利管理機制是保護與管理數位內容之存取權限的一種技術，它可以防止數位內容的資訊被未經授權的使用者所存取。為了降低傳輸與計算的成本，Chang et al. (2010) 提出了一個適用於行動網路上的企業數位權利管理機制。然而在他們的方法中，當行動用戶的行動設備遺失或被竊時，合法使用者的身份易被他人偽冒；此外，他們的方法缺乏使用上的彈性，且對於行動設備的計算負擔仍舊太高。為了解決上述缺點，本文提出了一個適用於行動通訊設備之企業數位權利管理機制，不但解決了行動設備遺失所衍生的安全性問題，且在設備之使用及驗證上更具彈性，更大幅降低設備的計算成本。本文所提之方法不僅兼顧了企業數位權利管理的安全性與便利性，同時對於電子商務的發展也有著極大的助益。

Enterprise Digital Rights Management (E-DRM) is a technology for protecting and managing the access rights of digital contents. To reduce the communication and computation costs of mobile users, Chang et al.
(2010) proposed an efficient and reliable E-DRM scheme for mobile environments. However, we find that their scheme is insecure if the mobile device has been lost or stolen. Besides, their scheme is not efficient and flexible for mobile users. To solve the above problems, we propose a new E-DRM scheme for mobile devices in this paper. The proposed scheme can protect the digital content even if the mobile device has been lost or stolen. In addition, it is more flexible and efficient than the related works for mobile users. Therefore, the proposed E-DRM scheme provides high security and convenience for enterprises to protect digital contents. In addition, it also has lots of benefits in the development of electronic commerce.