A certificate-free online/offline searchable ciphertext method

Abstract

The invention provides a certificate-free online / offline searchable ciphertext method, which divides the certificate-free searchable encryption process into two stages: offline and online. The offline stage has nothing to do with keywords, and the online stage requires the participation of keywords. After completing the necessary preparations, the data owner generates offline ciphertext and file ciphertext in the offline stage, generates online ciphertext in the online stage, and sends the offline ciphertext, file ciphertext and online ciphertext to the server. Before the data user retrieves the ciphertext of the file, an offline trapdoor is generated in the offline stage, an online trapdoor is generated in the online stage, and then the offline trapdoor and the online trapdoor are sent to the server. After the server passes the verification, notify the data user to download the ciphertext of the file, otherwise, terminate the related operation. The present invention is very effective when the computing resources or storage resources of the data owner and the data user are limited, and the offline phase and the online phase are carried out successively, and the computing resources or storage resources are occupied respectively, which can reduce the trouble of common occupation.

Description

technical field [0001] The invention belongs to the technical field of network security, in particular to a certificate-free searchable ciphertext method, in particular to a certificate-free online / offline searchable ciphertext method. Background technique [0002] With the development of network technology and computer storage technology, network costs and storage costs have also been greatly reduced. Especially with the current cloud storage technology, more and more users are willing to outsource data, especially those with limited computing and storage resources. Mobile devices. The most important role in data outsourcing is the server, but the server is not safe and often becomes the target of network attacks. In order to protect the privacy and security of user data, the data owner encrypts the data before outsourcing the data, and then uploads the ciphertext to server, but the subsequent search and retrieval of ciphertext becomes troublesome, and searchable encryptio...

AI Technical Summary

Problems solved by technology

[0004] There are some deficiencies in the existing searchable encryption methods without certificates, one of which is that they fail to consider the limited computing or storage resources of users, especially the widespread use of mobile devices today, such as smartphones, if All calculations of searchable encryption are done online, which inevitably leads to low efficiency of searchable encryption due to limited computing or storage resources. There is currently no effective solution to this problem

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