「雲端運算」為新興的運算服務模式，然而，由於它的特殊性，衍生「安全」的議題，特別是機敏資料，再者「雲端運算」也必須考慮低運算能力設備的存取需求。因此，本研究整合「情境」和「屬性」的概念，規劃細粒度資料存取控制模式，在這模式中，以輕巧的密碼運算或少低運算能力設備的運算消耗及籍由誠信的資料控制伺服器代替資料擁有者進行授予及撤銷使用者存取權。

Although cloud computing is an emerging computing service model, its unique features raise the issue of security, particularly with regard to the confidentiality of data. Moreover, the devices used with this approach often have relatively low computing power. This study integrates the concepts of both context and attributes to propose a fine-grained data access control model. To reduce the computational overhead, and thus raise efficiency while enabling devices with low computing power to operate properly, the proposed model employs lightweight cryptographic operations on the user side, and uses a trusted data control server to be responsible for granting and revocation of user privileges, instead of the data owner.