中文摘要：

数字版权管理（digital rights management,DRM）是我国信息化建设的重要内容.但高昂的投资成本和欠佳的用户体验是其进一步推广的瓶颈.而已有的采用云计算解决DRM瓶颈问题的研究大都只着眼于云计算的存储服务功能,较少关注云计算的计算优势.提出了一种云计算环境下支持属性撤销的外包解密DRM方案.考虑到DRM中用户隐私保护的问题,提出用户通过匿名标签购买许可证.此外,为了充分发挥云计算在计算上的优势以及可以灵活、细粒度地撤销用户的属性,提出了一种支持属性撤销的外包解密CP-ABE（ciphertext-policy attribute-based encryption）机制.与已有的基于云计算的数字版权保护方案相比,提出的方案在保护内容和用户隐私的同时,支持灵活的访问控制机制和细粒度的用户属性撤销,并且支持CP-ABE的解密外包计算,方案具有较好的实用性.

英文摘要：

DRM（digital rights management）is an important part of the construction of informatization in China.Unfortunately,high investment costs and poor user experience are two issues of DRM for further promotion in practice.Previous studies for DRM focused merely on storage service of cloud computing,lacking of concerning on the advantage of its computing service.This paper proposes a DRM scheme supporting attribute revocation and outsourced decryption in the cloud computing environment.In order to protect the user＇s privacy in the DRM system,we propose that users purchase licenses through anonymous tags.In addition,in order to give full play to the advantages of cloud computing in computing and be flexible,finegrained revocation of the user＇s attributes,a supporting revocation of the outsourcing decryption CP-ABE scheme is proposed.Compared with the existing digital rights management schemes based on cloud computing,the proposed scheme protects content security and user privacy.Besides,it supports flexible access control mechanism and fine-grained user＇s attributes revocation,and it is more applicable in the content protection in the cloud computing.