中文摘要：

为了提升可搜索公钥加密方案中服务器端关键字的搜索效率,提出了基于拉格朗日多项式的互逆映射构造方法和支持多关键字的可搜索加密公钥方案.该方案中,每组关键字对应一对互逆映射,发送者将该组关键字密文的变换结果输出给服务器,接收者向服务器发送陷门,只有当陷门关键字属于该组关键字时,服务器才能还原出陷门关键字的密文以进行匹配计算,仅需一次双线性对计算即可搜索多个关键字.该方案在标准模型中是语义安全的,关键字匹配效率较高且没有限制条件.

英文摘要：

In order to improve the server-side keywords-searching efficiency in public key encryption by keyword search schemes, we propose a method of constructing reciprocal maps based on lagrange polynomial and a public key encryption by multi-keywords search scheme.In the scheme,each couple of reciprocal maps corresponds to a set of keywords.The sender makes ciphertext transformation for the set of keywords,and sends the result to the server.The receiver sends a searching-keyword trapdoor to the server.The server can restore the ciphertext of the keyword corresponding to the trapdoor for matching,only if the keyword belongs to the set.Only one pair computing is required to finish multi-keywords searching.The scheme is semantically secure in the standard model,and has a high efficiency of keywords searching with no restriction.