关键词: 多关键字分级检索, 同态加密, 向量空间模型, 云计算

Abstract: To satisfy the requirement for multi-keyword searching over encrypted data, and solve the problem of privacy preserving and data security of the users, a modified multi-keyword ranked searchable encryption scheme is proposed. The scheme utilizes the vector space model to construct the searchable index and uses the improved homomorphic encryption algorithm to encrypt and decrypt data. It also supports the ranked result, which effectively avoid returning the low relevance documents. Further thorough security analysis and performance evaluations show that the scheme provides [CCA2]security and how effectively improves system performance and reduce communication cost and eliminates unnecessary traffic.

Key words: multi-keyword ranked search, hommomorphic encryption, vector space model, cloud computing