Searchable encryption method based on wildcard character in cloud storage safety

Abstract

The invention relates to a searchable encryption method based on wildcard character in cloud storage safety. The method comprises the following steps that: setting a document to be uploaded; extracting a keyword set; encrypting the keyword set; selecting a random number as a document encryption key, and encrypting the document encryption key; encrypting the document to be uploaded to obtain a ciphertext, and sending the ciphertext to a cloud computing platform; input a query keyword set, generating a query trapdoor, carrying out signature, and sending the signature to the cloud computing platform; verifying a query signature by the cloud computing platform, and executing a search algorithm by the cloud computing platform; transmitting a keyword index and the query trapdoor into a keyword matching protocol to obtain an encryption matching result; carrying out decryption to obtain a search result; according to the search result, returning a corresponding ciphertext by the cloud computing platform; and recovering the document encryption key, and recovering the document. By use of the method, the keyword search of at most two wildcard characters can be supported, the wildcard character can appear on any position of the keyword, and a plurality of random characters can be represented.

Description

technical field [0001] The invention relates to a searchable encryption method based on wildcards in cloud storage security Background technique [0002] Cloud storage provides users with ubiquitous, dynamic, scalable and on-demand storage services. While cloud storage brings more convenience to users, it also poses serious security threats to user data. To protect the privacy of outsourced data in public cloud servers, data encryption is an effective way to prevent internal / external attackers from accessing sensitive information. At the same time, in order to facilitate the use of data, it is necessary for us to support users to perform keyword queries on ciphertext (without decryption). This mechanism is called searchable encryption. [0003] Consider electronic health record (EHR) storage systems as an example of an application for searchable encryption. Assuming user Alice wants to store sensitive EHR data in the public health cloud server, she first needs to extract...

AI Technical Summary

Problems solved by technology

The disadvantage of the Bloom filter is that the false positive probability (false positive probability) cannot be ignored

[0008] Existing fuzzy searchable encryption schemes are limited in that they can only correct small edit distance errors, such as misspellings

The disadvantage of this scheme is: a wildcard can only represent one character

[0011] The disadvantage of searchable encryption schemes based on Bloom filters is that the false positive probability is not negligible

Because the hash function may map one or more elements to the same position of BF, there is a false positive probability in the Bloom filter

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