关键词: 可搜索加密, 多关键字搜索, 安全性证明, 隐私, 云存储

Abstract:

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.

Key words: searchable encryption, multikeywords search, security proof, privacy, cloud storage