关键词: 安全搜索引擎, 云存储, 属性加密（ABE）, 代理重加密, 可回取证明

Abstract: This paper analyzes the major cloud service providers’ key technology and security mechanism to extract the security requirement of current popular cloud services. And based on this analysis, this paper proposes a security framework which integrates cryptography algorithms as attribute-based encryption (ABE), proof of retrievability and proxy re-encryption to ensure the confidentiality, integrity, availability of cloud data. Furthermore, this paper implements a prototype of cloud storage service based efficient search system which employs ABE for fine-grained access control to protect unauthorized users’ access to sensitive file information (abstract, keywords) during search process and at the same time keeps the efficiency.

Key words: secure search engine, cloud storage service, attribute-based encryption (ABE), proxy re-encryption, proof of retrievability