An Attribute-Based Outsourcing Scheme for Bgn-type Ciphertext Decryption

Abstract

The invention particularly relates to a BGN type cryptograph decryption outsourcing scheme based on attributes. The scheme comprises steps that (1), a system parameter is set, and an encryption secret key is generated; (2), an access structure is selected by a sending side, message encryption is carried out, and cryptograph is generated; (3), a main secret key and the attributes are inputted by a receiving side, and a conversion secret key and a private secret key are outputted; (4), the cryptograph is sent by the sending side to a cloud end; (5), the conversion secret key is sent to the cloud end by the receiving side; (6), the cryptograph is converted by the cloud end through utilizing the conversion secret key to acquire a part of the cryptograph which is sent to the receiving side; and (7), the private secret key is utilized by the receiving side to decrypt the part of the cryptograph to acquire a message, and homomorphic computation operation for the cryptograph carried out by the cloud end is further comprised between the step (4) and the step (5). The scheme is advantaged in that not only can system decryption efficiency be improved, but also storage cost of a receiver is reduced; according to the cryptograph acquired according to the encryption method, a server is permitted to carry out multiple addition homomorphic operation and multiplication homomorphic operation for cryptograph data, on the condition that decryption difficulty does not increase, CPA safety of the user information is substantially improved.

Description

technical field

[0001] The invention belongs to the technical field of information security, and in particular relates to an attribute-based BGN type ciphertext decryption outsourcing scheme. Background technique

[0002] The introduction of the concept of cloud computing has brought the development of the information industry into the fast lane. Cloud services not only provide users with massive storage services and powerful computing capabilities, but also promote economic development. Public clouds are mainly maintained and operated by untrustworthy third-party service providers, and security issues associated with cloud computing are also increasing. highlight. Cloud security is considered to be the biggest challenge among many difficulties faced by the practical application of cloud services, and it is also the biggest problem that cloud services need to solve urgently. If the user saves sensitive data to the cloud server in plain text, the cloud may copy or even tamp...

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