基于改进DGHV算法的云存储密文全文检索研究

Research on Ciphertext Full-text Retrieval of Cloud Storage Based on Improved DGHV Algorithm

为了有效解决云存储中用户数据的机密性问题,文章提出一种基于同态加密的云存储密文全文检索方法。文章首先介绍了同态加密,并研究了基于DGHV算法的密文检索方案。接着提出一种基于改进DGHV算法的方案用于云存储密文全文检索。该方案采用两个密钥对明文关键词进行同态加密,一个为只有用户知道的用户密钥,另一个为用户与云服务器共享的检索密钥。用户检索文件时,云服务器只需利用检索密钥就能对文件进行全文检索,而用户密钥始终仅保留在用户手中,云服务器无法获取,也就无法解密出用户的明文数据。该方案可以在第三方服务器不可信的云存储场景下实现高效的检索,保证了用户数据的机密性。

In order to solve the confidentiality problem of user data in cloud storage effectively,this paper presents a ciphertext full-text retrieval method of cloud storage based on homomorphic encryption.This paper first introduces homomorphic encryption and studies the ciphertext retrieval scheme based on DGHV algorithm.A scheme based on improved DGHV algorithm is then proposed in this paper for ciphertext full-text retrieval of cloud storage.The scheme uses two keys to perform homomorphic encryption on the plaintext keywords.One is a user key that only the user knows,and the other is a retrieval key shared by the user and the cloud server.When a user retrieves a file,the cloud server can perform a full-text retrieval operation on the files only by using the retrieval key,while the user key is always retained only on the user5s side,and the cloud server cannot obtain it to decrypt the ciphertext data of the user.The scheme can realize efficient retrieval under the third-party server untrusted cloud storage scenario,and ensure the confidentiality of user data.