中文摘要：

云环境中常采用属性基加密机制进行一对多的数据共享,这种方式会影响到系统效率,数据拥有者在更新加密密钥时操作复杂。针对此问题,提出一种支持快速密钥更新的数据分享方案。数据拥有者使用属性基加密数据密钥并传送给数据中心,重加密机制支持密钥的快速更新,降低了用户和服务器的工作量,并提高系统安全性。方案基于判定双线性Diffie-Hellman（Decision bilinear Diffie-Hellman,DBDH）假设,在标准模型下满足自适应选择明文攻击安全。通过与其他方案对比,该方案中属性密钥长度、密文长度有所优化,数据分享和读取数据计算开销有所减少,适用于移动终端云环境数据分享的性能需求。

英文摘要：

Attribute-based encryption（ ABE） is an optimal choice for one-to-many data sharing in the cloud environment, and is not very efficient when data owner updates the content key dynamically. In order to solve this problem, data sharing scheme supporting fast key updating in the encrypted database is proposed. In the scheme, the data owner encrypts the data key with attribute-based encryption mechanism. In addition, re-encryption mechanism is used to support the rapid updating of the data key. In this way,it can reduce the user and server workload and improve system security.The scheme is secure against chosen plaintext attack under the decision bilinear Diffie-Hellman （DBDH） assumption in the standard model. Compared with other schemes,the length of the attribute keys and ciphertext are optimized in the scheme. The cost of data sharing and accessing is reduced, which is more suitable for the practical application of cloud environment.