Distributed attribute-based encryption method supporting fine-grit attribute revocation on lattice

Abstract

The invention discloses a distributed attribute-based encryption method supporting fine-grit attribute revocation on lattice, and belongs to the field of the information security. The method comprisesthe following steps: at the system initialization stage: the linear secret sharing is performed on a target vector at a system initialization stage, a sub-secret sharing value is served as a privatekey of a corresponding attribute authorization mechanism, and the attribute authorization mechanism establishes the corresponding binary revocation tree for the managed system attribute; at the user attribute key and the update key generation stage: the attribute authorization mechanism obtains the secondary sub-secret sharing value of the user attribute by using secondary linear secret sharing, and the computes the user attribute key and the user attribute update key through a primary image extraction algorithm and a left-sampling algorithm; at the encryption stage: an encryption party computes the ciphertext of the message by using the Gaussian noise, the encrypted and preprocessed noise vector and the system public parameter; at the decryption: a decryption party decrypts the ciphertextby using the user attribute key and the user attribute update key. The method disclosed by the invention is high in security, flexible in access policy and supports the fine-grit attribute permissionrevocation.

Description

technical field [0001] The invention relates to a distributed attribute-based encryption method supporting fine-grained attribute revocation on a lattice. Background technique [0002] The 21st century is the information age. With the rapid development of Internet technologies such as electronic medical care, instant messaging, online shopping, and online video, information is changing human daily life in an unprecedented way. According to the "41st China Internet Statistical Report" released by China Internet Network Information Center (CNNIC), by the end of 2017, the number of Internet users in my country had reached 772 million, and the Internet penetration rate reached 55.8%, 4.1 percentage points higher than the global average. Huge groups of netizens have produced information and data of an unimaginable scale. Therefore, how to realize the safe storage of massive information and data has become an urgent problem to be solved in today's society. The attribute-based enc...

AI Technical Summary

Problems solved by technology

The analysis shows that the existing attribute-based encryption methods still have the following deficiencies: First, most of the existing attribute-based encryption methods use bilinear pairing construction, and their security is based on the Diffie-Hellman difficulty that has been proven to be difficult to resist quantum cryptanalysis Therefore, it is difficult for these methods to guarantee the confidentiality of stored data in the "quantum era"; in addition, these methods require a lot of time-consuming bilinear pairing operations in the encryption and decryption process, which is inefficient

However, this method can only implement the threshold access strategy using the Shamir secret sharing method, which is not flexible enough

In addition, the system is responsible for the distribution and management of all attribute keys in the system by a single attribute authority, so there is an attribute key custody problem and the security is not high