Attribute-based multi-mechanism hierarchical ciphertext-policy weight encryption method under cloud environment

Abstract

The invention discloses an attribute-based multi-mechanism hierarchical ciphertext-policy weight encryption method under a cloud environment. The method comprises steps: a central authority mechanism generates a global identifier AID or UID for a subordinate attribute authority mechanism or a user, and calculates an attribute weight segmentation set for each attribute in a system; the central authority mechanism randomly selects a bilinear pairing and a bilinear group, generates a system main key MK and a public key PK, retains the MK and publishes the PK; the central authority mechanism distributes the main key or a weight attribute private key for the subordinate attribute authority mechanism or the user; a data owner selects an access policy, encrypts a file and uploads the file to a cloud server; the user requests the cloud server for accessing to the encrypted file, the cloud server returns back a ciphertext CT, the user decrypts the file through the weight attribute private key, and if the attribute in the private key satisfies the access policy, the user obtains a plaintext. With the method provided by the invention, a graded hierarchical multiple-authority mechanism is established, and the authorities of different grades can be in charge of different attributes and distribute private key components.

Description

technical field [0001] The invention belongs to the technical field of network and information security, and in particular relates to an attribute-based multi-organization hierarchical ciphertext policy weight encryption method in a cloud environment. Background technique [0002] With the development of cloud computing, more and more users or enterprises choose to store data in the cloud. However, the outsourced storage mode of data can easily lead to unauthorized access. For example, cloud servers can obtain user data without user authorization and leak user privacy. In addition, the cloud server may also be subject to external threats, such as being attacked by hackers. For data security issues, most cloud service users encrypt their data before uploading. The traditional public key encryption method can guarantee data security, but it must know potential users in advance and use their public keys to encrypt data files separately, which lacks flexibility and operability...

AI Technical Summary

Problems solved by technology

However, it does not address the issue of multi-authority hierarchy

Images