Attribute encryption method and system supporting numerical attribute comparison access policy

Abstract

The invention discloses an attribute encryption method and system supporting numerical attribute comparison access strategy. The invention includes: converting the numerical attribute relationship comparison strategy in the access strategy into numerical range representation, and calculating the minimum prefix set of the numerical range; Convert the numerical attribute relationship comparison strategy to the "OR" threshold strategy connection of elements in the prefix minimum set; calculate the prefix family of the numerical attribute; convert the matching between the numerical attribute and the numerical attribute relationship comparison strategy to determine the prefix family and prefix Whether the intersection of the minimum set is empty, if not, it is determined that the numerical attribute satisfies the access control policy, and the decryption condition can be obtained; otherwise, it is determined that the decryption condition is not satisfied. The invention greatly improves the expression ability of the access strategy in the traditional attribute encryption technology by introducing the numerical attribute comparison expression strategy, and flexibly realizes the matching problem between the comparison relationship expression strategy and the numerical attribute in a unified manner.

Description

technical field [0001] The invention relates to an attribute-based encryption (Attribute-based Encryption) technology in the field of cryptography, in particular to an attribute-based encryption method and system supporting numerical attribute comparison access strategies. Background technique [0002] With the rapid development of cloud computing and big data, more and more enterprises and individuals begin to store their massive private data in the cloud center, which can not only greatly save the cost of local IT construction, but also benefit from the powerful cloud computing platform Functions store and process data. However, cloud computing data security has always been one of the key concerns. Because once data is outsourced to a remote cloud center, they will be out of the direct physical control of the data owner. Before users outsource data, encrypting data is one of the effective ways to protect data confidentiality. However, traditional cryptography can guaran...

AI Technical Summary

Problems solved by technology

Obviously, when the value space of the numerical attribute is very large, such conversion will bring about a rapid expansion of the strategy size, which is unrealistic in practical applications

In 2007, Bethencourt et al. discussed this issue in their ciphertext policy-based attribute encryption, and proposed a basic scheme, but did not solve this problem well.

The reason is that their method uses "AND" and "OR" thresholds to convert numerical attribute relationship comparison strategies. Since different conversion strategies need to be used for different relational operations, the complexity is very high, and the conversion methods are not uniform and inflexible.

In 2017, Xue et al. studied this problem again, and used 0-Encoding and 1-Encoding encoding to convert the relational comparison strategy into a bit string connected by the "OR" gate, but this method mainly considered ">" and "< "Two relational operations, lack of support for other comparative relational operations such as "≤", "≥", "≠"

Images