Content security sharing method and system based on proxy re-encryption

Abstract

The invention provides a content safe sharing method and system based on proxy re-encryption. A key server generates a public parameter and a system main key, and sends the public parameter to a system user; the key server generates a user private key and sends the user private key to each system user; a file uploading channel is provided to upload a file to a cloud server; the cloud server receives file ciphertext, keyword ciphertext, and a first layer of ciphertext; a file receiving end performs attribute-based decryption on the first layer of ciphertext; the cloud server searches ciphertext; the file receiving end receives the file ciphertext and decrypts, makes an access policy and generates a re-encryption key; and the cloud server re-encrypts the first layer of ciphertext by using the re-encryption key and then sends the encrypted first layer of ciphertext to a file sharing end. The invention provides a light, keyword search-supporting attribute-based proxy re-encryption method,so that massive original ciphertext and re-encrypted ciphertext can be accessed and controlled, a flexible access policy is supported, sharing efficiency is improved, and calculation burden of encryption and decryption is relieved.

Description

technical field [0001] The present invention relates to the technical field of information security, in particular to a method and system for content security sharing based on proxy re-encryption, and in particular to a lightweight content security sharing method based on proxy re-encryption for large-scale users. Background technique [0002] With the development and popularization of cloud computing, the security of user data faces new threats and challenges. Because the number of users in the cloud environment is large, and the data management rights belong to third-party servers, users generally encrypt data before uploading in order to protect their privacy and data security. But when the data is encrypted, traditional access control, file search and sharing techniques are no longer applicable. In order to effectively realize the access control, file search and sharing of encrypted data, a variety of new cryptosystems have been proposed one after another. Among them, ...

AI Technical Summary

Problems solved by technology

Its shortcomings are: the original ciphertext is not obtained through attribute-based encryption, so the original ciphertext does not have large-scale access control functions; and it does not provide a decryption method for the original ciphertext and re-encrypted ciphertext

Its shortcoming is: the access control is not flexible, it only supports the access structure connected with the "AND" gate, and it can't do anything about the "OR" logic or threshold control

Its shortcoming lies in: the complexity of the algorithm is high, and the efficiency is low in practical application

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