中文摘要：

云是一个新兴的计算范例。它从学术界和工业引起了广泛的注意。但是它的安全问题在它的快速的发展被看作了一个批评障碍。当数据主人在云作为纯文本存储他们的数据时，他们由于任意的可接近性失去他们的云数据的安全，特殊由未信任的云存取了。为了保护数据主人的机密，遮蔽数据，一个有希望的想法是在在云存储他们前由数据主人加密数据。然而，自从它是难的让数据主人管理他们的私人钥匙，传统的加密算法的直接雇用不能解决这个问题很好，如果他们想要安全地以一种有细密纹理的方式与其它一起分享他们的云数据。在这份报纸，我们建议一个有细密纹理、异构的代理重新加密(FH-PRE ) 系统保护数据主人云数据的机密。由在云使用 FH-PRE 系统，数据主人云数据能安全地在云被存储并且以一种有细密纹理的方式分享了。而且，异质支持使我们的 FH-PRE 系统比以前的工作更有效。另外，在二个异构的云系统之间分享提供安全数据，它与不同密码的原语被装备。

英文摘要：

Cloud is an emerging computing paradigm. It has drawn extensive attention from both academia and industry. But its security issues have been considered as a critical obstacle in its rapid development. When data owners store their data as plaintext in cloud, they lose the security of their cloud data due to the arbitrary accessibility, specially accessed by the un-trusted cloud. In order to protect the confidentiality of data owners＇ cloud data, a promising idea is to encrypt data by data owners before storing them in cloud. However, the straightforward employment of the traditional encryption algorithms can not solve the problem well, since it is hard for data owners to manage their private keys, if they want to securely share their cloud data with others in a fine-grained manner. In this paper, we propose a fine-grained and heterogeneous proxy re-encryption （FH- PRE） system to protect the confidentiality of data owners＇ cloud data. By applying the FH-PRE system in cloud, data owners＇ cloud data can be securely stored in cloud and shared in a fine-grained manner. Moreover, the heteroge- neity support makes our FH-PRE system more efficient than the previous work. Additionally, it provides the secure data sharing between two heterogeneous cloud systems, which are equipped with different cryptographic primitives.