Efficient searchable symmetric encryption method and system with forward and backward security

Abstract

The invention discloses an efficient searchable symmetric encryption method and system with forward and backward security, and belongs to the field of cloud storage security, and the method comprisesthe steps: enabling a retrieval client to generate a ciphertext, and transmitting the ciphertext to a retrieval server, so as to store the ciphertext in a ciphertext database; wherein the generated ciphertext comprises a ciphertext index, a random bit string, ciphertext meta-information and an encrypted file identifier; wherein the ciphertext meta-information comprises an operator of the ciphertext, a ciphertext index and a retrieval trap door of the previous operation, and a to-be-deleted ciphertext index; when keyword retrieval is carried out, enabling the retrieval client to acquire a fileidentifier and an operator related to a keyword from the private state table to generate a ciphertext index and a retrieval trap door, and send the ciphertext index and the retrieval trap door to theretrieval server; and enabling the retrieval server to obtain all the ciphertext related to the keyword from the ciphertext database, delete the ciphertext needing to be deleted to obtain a result set, and send the result set to the retrieval client. The searchable ciphertext is efficiently retrieved, and meanwhile, the forward and backward security is ensured.

Description

technical field [0001] The invention belongs to the field of cloud storage security, and more specifically relates to a searchable symmetric encryption method and system with high efficiency and forward-backward security. Background technique [0002] With the gradual maturity of cloud computing and cloud storage technology and the gradual reduction of costs, users are more inclined to save their files and other data in the cloud, that is, outsourced storage of data. The outsourced storage technology enables users not to worry about data failure caused by damage or loss of their local devices, and frees up the limited storage space of users' local devices. But this also brings about a problem, that is, how users can protect the private information in their own data from being obtained by the server. The main way to solve the problem of data privacy protection in outsourced storage technology is to encrypt the data before uploading it. In order to make the data still have g...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defects and improvement needs of the prior art, the present invention provides an efficient searchable symmetric encryption method and system with forward and backward secur

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