Cloud storage oriented ciphertext full-text search method and system based on full homomorphic ciphers

Abstract

The invention discloses a cloud storage oriented ciphertext full-text search method and system based on full homomorphic ciphers. The method comprises that a data owner uploads document IDs, encrypted document ciphertexts and an encrypted document inverse index table to a cloud server; hash operation is carried out to the document terms on the inverse index table; TF (Term frequency) and IDF (Inverse document frequency) values are encrypted by a full homomorphic technique on integers; a public key certificate is issued to a data user; the data user carries out hash operation to to-be queried keywords and uploads to a cloud service provider; the cloud service provider compares and searches the hash operation values of the to-be queried keywords and the hash operation values of the document terms on the inverse index table; and the cloud service provider carries out full homomorphic multiplication and add operations. According to the method and the system of the invention, the calculation is carried out in a ciphertext state; in the calculation process, any information related to the documents will not be leaked to the cloud service provider and other attackers; the data privacy of the data owner and the query data privacy of the data user are protected; and moreover, the controllability of the data right of use is realized.

Description

Technical field [0001] The invention belongs to the technical field of cloud storage and cloud security related software, and more specifically relates to a ciphertext full-text retrieval method and system for cloud storage and based on a fully homomorphic password. Background technique [0002] Currently, major IT companies have launched free cloud disk (also known as cloud disk) storage services, such as Baidu Cloud Disk, Tencent Weiyun, Jinshan Kuai Disk, etc., because of their large capacity and can be accessed at any time through the network, attracting The bigger the user, the more users. However, security issues are the most critical issue facing the current development of cloud computing. Cloud users’ distrust of cloud storage service providers has become an important factor restricting the promotion of cloud storage. In the cloud storage mode, the user's data is stored in the cloud provider, which means that the user's data (including sensitive data) is completely manag...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the existing application requirements, the present invention provides a full-text retrieval method and system for ciphertexts based on fully homomorphic cryptography oriented to cloud storage. The server can perform relevant calculation operations on the ciphertext, and realize the document full-text retrieval service in the ciphertext state, thereby solving the technical problems of poor user privacy, poor controllability of data usage rights and low retrieval efficiency existing in existing methods

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