Abstract:

In order to effectively protect the security of outsourced data, it satisfies the problem of users efficiently searching data stored in the cloud. A cloud storage full-text retrieval scheme based on homomorphic encryption is proposed. Based on the integer vector encryption technology, the scheme establishes a vector space model, and then calculates the cosine similarity between the search vector and the document vector in ciphertext for retrieval. The scheme utilizes the homomorphism of the encryption algorithm. During the process of uploading files, retrieving and downloading files, the cloud server cannot obtain plaintext data, and the scheme can perform multi-keyword retrieval. It has accurate and higher retrieval efficiency in the third-party untrusted cloud storage scenario. The scheme description is simple, ensuring the confidentiality of user data, and has good application in practical applications.

Key words: cloud storage, homomorphism, vector space model, integer vector encryption, multiple keywords

摘要：

为了有效保障外包数据的安全性，满足用户高效检索储存在云中的数据。提出一种基于同态加密的云存储全文检索方案。该方案以整数向量加密技术为基础，建立向量空间模型，进而在密文下计算检索向量与文档向量的余弦相似度，进行检索。方案利用加密算法的同态性，在上传文件，检索以及下载文件的整个过程中，云服务器均无法获取明文数据，方案可进行多关键词检索。在第三方不可信云存储场景中具有准确和更高的检索效率，方案描述简单，保证了用户数据的机密性，在实际场景中具有良好的应用。

关键词: 云存储, 同态性, 向量空间模型, 整数向量加密, 多关键词