Multi-authority attribute-based encryption method based on blockchain

Abstract

The invention provides a multi-authority attribute-based encryption method based on a blockchain, which comprises the following steps of: globally initializing a system, generating a system general parameter (GP), and recording the GP into a genesis block; initializing attribute authority, wherein all the attribute authority generates a group of attribute public and private keys by using the GP; encrypting data, wherein an encryptor generates a data ciphertext and a key ciphertext by using symmetric encryption and attribute encryption algorithms; generating a user private key, wherein the attribute authority generates a group of attribute private keys for the user; decrypting the data, wherein the user decrypts the ciphertext by using the attribute private key to obtain shared data; and revoking the attribute, wherein due to user attribute revocation, an attribute set does not meet an access strategy, and a updated ciphertext address cannot be obtained. According to the invention, the blockchain is utilized to record the time sequence attribute state of the user, so that distributed distribution, storage and revocation of the attribute private key are realized, the key management efficiency of a distributed attribute-based encryption mechanism is improved, and the security of data sharing in a distributed environment is enhanced.

Description

technical field [0001] The invention relates to the field of attribute-based encryption and block chain technology, in particular to a multi-authoritative attribute-based encryption method based on block chain. Background technique [0002] With the development of Internet and cloud computing technology, more and more sensitive data are shared and stored in untrusted third-party servers, and its security issues have aroused great concern. The traditional public key encryption mechanism can only achieve coarse-grained access control, and its efficiency is low. Therefore, Sahai and Waters first proposed the concept of fuzzy identity-based encryption (Fuzzy Identity-Based Encryption, FIBE) in 2005 on the basis of identity-based encryption mechanism, and introduced the concept of attribute-based encryption mechanism (Attribute-Based Encryption, ABE ). Different from the traditional IBE mechanism, the identity of each user is described by a set of characteristic attributes. The...

AI Technical Summary

Problems solved by technology

However, these MA-ABE schemes have only been shown to be selectively safe

In practical applications, the user's attribute private key needs to be revoked, and the existing user revocation mechanism needs to increase a large amount of computing overhead, and it is difficult to realize the revocation of a single user attribute

The existing attribute revocation mechanism has a large amount of calculation, and does not meet the problems of forward or backward security, and cannot manage user attributes dynamically and efficiently.

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