Multi-keyword plaintext and ciphertext retrieving method and device oriented to cloud storage

Abstract

The invention relates to a multi-keyword plaintext and ciphertext retrieving method and device oriented to cloud storage and relates to the field of information safety. The method includes the following steps that firstly, a client terminal performs lexical analysis according to inquiry statements and generates plaintext keywords; secondly, a corresponding user index encryption key is obtained according to a main key bound with the identity of a user, and the plaintext keywords are encrypted with the encryption algorithm of the index encryption key, and ciphertext keywords are generated; thirdly, multi-keyword ciphertext retrieving is performed on a ciphertext index in a cloud storage server according to an inquire tree generated by the client terminal, and retrieved data element information and retrieved relevancy scores undergo inquiry result merging and sequencing; fifthly, inquiry result merging and sequencing are performed in the cloud storage server with the same method; sixthly, a unified sequence result is sent to the client terminal, and an inquiry result is displayed to the user. According to the multi-keyword plaintext and ciphertext retrieving method and device oriented to the cloud storage, a key management scheme which is higher in safety degree is provided, plaintext and ciphertext united retrieving can be supported and multi-keyword retrieving can be provided.

Description

technical field [0001] The invention relates to the field of information security, in particular to a method and system for retrieving user ciphertext data in a cloud storage environment. Background technique [0002] With the emergence of smart phones, network access devices are increasingly diversified, and these smart terminals connected to the network often have certain data acquisition, storage and processing capabilities, and users need to maintain a unified user view on different terminals. At the same time, the increasing popularity of cloud computing provides convenience for users to access cloud storage. For example, Baidu Cloud Disk provides users with 1T of free online storage space; Amazon's cloud service provides both storage space and computing power. Users only need Get massive computing and storage resources for a low fee. [0003] These cloud computing solutions solve the user's demand for backing up files to a certain extent, but there are significant fla...

AI Technical Summary

Problems solved by technology

[0009] 1) Low execution efficiency

The existing technical scheme encrypts all the user's data when encrypting, but in fact, most users only have a few sensitive files that need to be encrypted, and other files only need to be synchronized and backed up

[0010] 2) Low efficiency of ciphertext query

Once the data is encrypted, the original sequence relationship of the data will be destroyed, making the original index mechanism no longer available. When the user searches, he has to retrieve all the ciphertexts, and after decryption, he will judge whether it is the data he needs, which will return a large number of ciphertexts. Useless information, low execution efficiency

[0011] 3) Plain and ciphertext cannot be retrieved jointly

It is necessary to search for plaintext files and ciphertext files separately, and it is impossible to form a complete data view through a unified retrieval interface

[0012] 4) Multi-keyword search is not possible

Multiple single-keyword searches are required to achieve the search purpose, which will increase data transmission and server burden, and reduce user experience at the same time

[0013] 5) The key management scheme is insecure

[0014] In summary, a clear and ciphertext retrieval method that can effectively improve the user's data security protection and privacy protection capabilities, improve the efficiency of ciphertext storage, and promote the development of cloud computing and increase the efficiency of information system use needs to be proposed.

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