摘要： 公钥可搜索加密能实现基于密文的信息检索,适用于云计算环境。但现有公钥可搜索加密方案普遍依赖 于双线性对,并且无法对服务器返回的搜索结果进行验证,效率和安全性较低。为此,基于ElGamal 加密算法提出 一种可验证的公钥可搜索加密方案。该方案使用ElGamal 加密算法替代双线性对运算,与传统算法相比具有较低 的计算复杂度,并且易于实现。在密文关键词及加密文件生成算法中,采用ElGamal 签名算法对关键词的哈希值 进行数字签名。当收到服务器返回的搜索结果后,用户可以通过计算得到发送者的公钥,并对相应的签名值进行 验证,从而有效防止服务器返回错误结果。

关键词: 可搜索加密, 公钥, 密文关键词, 验证, 关键词搜索, ElGamal 加密

Abstract: As an attractive cryptographic primitive,the public key searchable encryption enables users to search on encrypted data,and hence is applicable to the setting of cloud computing. But most of the existing schemes have to adopt the bilinear pairing and fail to verify search results from the server. Accordingly,these schemes suffer drawbacks in terms of efficiency and security. Aiming at this problem,based on the ElGamal encryption algorithm,a new verifiable scheme is proposed. It has more desirable computation efficiency and is easy to implement in because it replaces the bilinear pairing with the ElGamal encryption. Especially,during the generation of encrypted keywords and encrypted files,the new scheme can generate the digital signature of the hash value of keywords based on the ElGamal signature algorithm. Upon receiving the search results from the server,users can obtain the public key of the sender,and then verify the ElGamal signature, which effectively prevents the server from returning wrong results.

Key words: searchable eneryption, public key, encrypted keyword, verification, keyword search, ElGamal encryption

中图分类号: 

• TP309