Verifiable semantic security multi-keyword search method in cloud storage

Abstract

The invention relates to a verifiable semantic security multi-keyword search method in cloud storage. The method comprises the following six steps: initializing the system, establishing a shared key between a TA and a data owner, encrypting the data document and its index by the data owner, generating a query trapdoor by the TA, performing security query by a cloud server, and querying a user verification query result. The method realizes the semantic security multi-keyword connection query of the encrypted index by inner product predicate encryption and dual system encryption, and implementsfine-grained authorization and overcomes the shortcomings of the traditional "0" or "1" authorization model by introducing a trusted TA. The TA verifies the query user's query qualification and sendsa query trapdoor for the authenticated user, which solves the problem that the data owner needs to be online always. The method, which can achieve fine-grained authorization, resist dictionary attacks, and verify the correctness of query results, is a semantic security multi-keyword search method.

Description

technical field [0001] The invention relates to the technical field of encrypted search, in particular to a multi-keyword search method with verifiable semantic security in cloud storage. Background technique [0002] Cloud computing, as a new computing model after distributed computing and grid computing, can provide powerful data storage, management and computing capabilities. In recent years, with the rapid development of cloud computing, many companies or organizations have begun to outsource data to cloud servers, which not only enables users to access remote data anytime and anywhere, but also reduces users' local computing and maintenance costs. However, cloud servers are maintained and managed by third-party Internet commercial companies (such as Amazon, Google, etc.), and usually do not belong to the same trust domain as users. Therefore, while cloud computing brings convenient services, it may also cause severe security risks. In order to protect data security an...

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Problems solved by technology

However, in this scheme, the user's authorization still adopts the "0" or "1" authorization model. Once the user is authorized, the user management agency will send the key that can be used to generate the query trapdoor to the querying user, that is, the authorized key. The "1" model, such an authorization method allows users to request any multi-keyword connection query, which cannot meet the requirements in many applications, and there is no query result verification function in this solution

[0007] The Chinese patent with the application number CN201711332605.0 "Certificate-free verifiable multi-keyword ciphertext query system and method" specifically relates to a non-certificate verifiable multi-keyword ciphertext query system and method, which introduces a key In this scheme, the key generation center is different from the traditional ciphertext query based on the public key encryption algorithm. In this paper, the key generation center is also assumed to be untrustworthy. The information generates a partial private key, and the data owner and data user generate a complete private key based on the partial private key and secret value, so that the key generation center cannot obtain the private key of the data owner and data user, thus increasing the protection of the private key. safety

However, in this technical solution, the user’s authorization description is not clear, and before the data owner outsources the data, the data owner uses the public key encryption algorithm to encrypt the plaintext document set. Since the public key encryption algorithm has the characteristics of slow encryption speed, all Encrypting relatively large plaintext files with public key algorithms is impractical

Moreover, this technical solution only provides a technical framework, and does not provide a specific algorithm description

[0008] Moreover, the four existing technologies listed above are not semantically secure, which is not enough security for applications with semantic security requirements

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