An Identity-Based Hierarchical Encryption Method on Lattice

Abstract

The present invention discloses a new grid-based hierarchical identity-based encryption (HIBE) method. The method is implemented according to the following steps: first, using an implicit extension method to optimize the original image sampling algorithm in HIBE; then in combination with the MP12 trapdoor deviation algorithm, proposing an efficient HIBE user key extraction algorithm; and based on this algorithm and in combination with the LWE algorithm, completing the HIBE method construction. The efficiency of the method disclosed by the invention increases both in the system establishment and the user key extraction stage, and the trapdoor size and the system hierarchy depth increase only linearly, and the optimized original image sampling algorithm can solve the problem of Gauss Parameters growth after the trapdoor derivation of the MP12 trapdoor derivation algorithm to some extent. In summary, the present invention has a higher practical feasibility.

Description

technical field [0001] The invention relates to the technical field of information security, in particular to a hierarchical identity-based encryption method on a grid. The method has the characteristics of anti-quantum computing analysis and can be used to reduce the burden of a key generation center in a large-scale network. Background technique [0002] Identity-based encryption (IBE, identity-based encryption) is a kind of public key encryption system, which uses the user's unique identity (such as mobile phone number, email address, etc.) The private key generation center (KGC, key generation center) uses the system master private key to generate. The identity-based encryption system was first proposed by Shamir in 1984. Until 2001, Boneh et al. defined the security model of IBE and gave a specific scheme construction based on the BDH (Bilinear Diffie-Hellman) problem. Since then, the research of IBE has quickly become a hot spot in the field of cryptography, and many ...

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Problems solved by technology

In 2010, Cash et al. proposed a trapdoor derivation algorithm on Eurocrypt'10, and constructed the first HIBE scheme on the grid based on this algorithm. This scheme regards the user identity as a series of bits and assigns A uniform random matrix, which will cause the dimension of the lattice to increase significantly with the increase of the depth of the system classification, and the derived trapdoor size of the proposed trapdoor derivation algorithm has a quadratic growth relationship with the depth of the system classification. In the HIBE system with high hierarchical depth, there will be a problem that the size of the trapdoor is too large and the system cannot be used normally

But at the same time, we noticed that the derived algorithm of MP12 also has shortcomings. Compared with the derived trapdoor of the trapdoor derived algorithm, the quality of the trapdoor, that is, the maximum singular value of the trapdoor matrix, will increase, resulting in the deterioration of the quality of the trapdoor, which in turn leads to A series of problems such as Gaussian parameter growth

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