中文摘要：

为了有效解决云服务器端密文数据检索效率不高的问题,基于双线性对,提出一种新的带关键字搜索的代理重加密方案.该方案将用户存储的数据分成文件、文件索引和文件对应的关键字后分别进行加密.在重加密阶段,不是采用传统方案中对文件密文进行重加密的方法,而是只对关键字密文重加密;在此阶段,仅需1次双线性对运算和1次指数运算,与已有的带关键字搜索的代理重加密方案相比,该方案具有较高的计算效率.在HDH困难假设下,证明该方案对适应性选择关键字攻击具有不可区分语义安全.另外,该方案不使用一次性强不可伪造签名,使得在云环境下更加安全有效.

英文摘要：

In this paper, a novel proxy re-encryption with keyword search scheme based on bilinear pairings is proposed. The scheme solves how to retrieve the ciphertext data in the cloud server and the low efficiency of retrieval. The user data after being divided into three parts,i, e. ,rile,rile index and the keyword corresponding to rile,will he encrypted respectively. In the re-encryption phase,the advanced scheme does not need to re-encrypt partial rile ciphertext,but re-encrypt the ciphertext of keyword corresponding to file. In addition, the scheme only needs a bilinear pairing operation and an exponential operation, which can improve the computation efficiency in comparison with congener schemes. It is proven to be with indistinguishability under adaptive chosen keywords attack in Hash Difrie-Hellman assumption. Furthermore, the scheme does not use any strongly-unforgeable one-time signature, making it more effective and safer in the cloud environment.