Attribute base encryption method and device

Abstract

The invention relates to an attribute base encryption method and device. The attribute base encryption method comprises the following steps: establishing an attribute base encryption system by a central mechanism; receiving a key sent by the central mechanism, wherein the key is generated by the central mechanism through a public parameter of the attribute base encryption system, a main key of the attribute base encryption system and a first user attribute, and the public parameter of the attribute base encryption system and the main key of the attribute base encryption system are generated according to a security parameter of the central mechanism; receiving a ciphertext sent by a second user, wherein the ciphertext is generated by the second user through an access control structure and the public parameter; and when the first user attribute satisfies the access control structure, decrypting the ciphertext by a first user through the key. Therefore, encryption and decryption algorithms have fixed calculation costs, the ciphertext has a fixed length, the correctness of the key generated by the central mechanism can be verified, and the monotonic access control structure can be realized.

Description

technical field [0001] The invention relates to the field of data security, in particular to an attribute-based encryption method and device. Background technique [0002] As a new computing model, cloud computing is being used by more and more users. However, data security in cloud computing has become the most concerned issue for users. In the traditional public key encryption method, the encryptor can use the recipient's public key to encrypt the message, so that only the recipient with the corresponding key can decrypt the ciphertext. Therefore, traditional public key encryption methods can only provide one-to-one secure data transmission. However, in cloud computing, one user needs to share confidential data to multiple users at the same time. In particular, users often want to utilize a descriptive set of attributes to indicate which users have access to their confidential data. Therefore, traditional public key encryption methods cannot be directly applied to prot...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the calculation cost of the encryption algorithm existing in the attribute-based encryption method in the prior art is proportional to the complexity of the access control structure adopted, the length of the ciphertext is proportional to the complexity of the access control structure adopted, and the decryption The algorithm is proportional to the complexity of the access co

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