Lattice-based homomorphic proxy re-encryption method capable of resisting strong collusion attack

Abstract

The invention relates to a lattice-based homomorphic proxy re-encryption method capable of resisting strong collusion attack. The invention relates to the technical field of information security, a lattice-based trap door technology is utilized to generate a re-encryption key so as to resist the strong collusion attack, and then a key exchange technology is utilized to construct a re-encryption ciphertext with homomorphic property, thus the lattice-based homomorphic proxy re-encryption method capable of resisting strong collusion attack is developed, so as to be suitable for a more complex cloud sharing environment. According to the lattice-based homomorphic proxy re-encryption method, the problem that a ciphertext is divided into two layers by a traditional anti-proxy re-encryption method, one layer is an original ciphertext used for protecting data, the other layer is a re-encryption ciphertext used for sharing, and the two layers are independently stored and need to be interacted isavoided. The proxy re-encryption method provided by the invention only relates to one layer of ciphertext, does not need to perform hierarchical processing on the ciphertext, and saves the interaction overhead.

Description

technical field [0001] The invention relates to the technical field of information security, and relates to a grid-based homomorphic proxy re-encryption method against strong collusion attacks. Background technique [0002] Proxy Re-Encryption (PRE) is especially suitable for data cloud sharing. In a cloud sharing system, due to the limitation of terminal storage space, users will store data in the cloud. Once the data is out of the user's control, it will bring about data security issues, so users generally encrypt the data and store it in the cloud. When the data owner wants to share the data stored in the cloud with another user (data user), the data owner can use his private key and the data user's public key to generate a re-encryption key and send it to the cloud service business. The cloud service provider can use the re-encryption key to convert the ciphertext of the data owner into the re-encryption ciphertext of the data user. During this process, the cloud serv...

AI Technical Summary

Problems solved by technology

The re-encryption key constructed by the key exchange technology uses the data user's public key to encrypt the data owner's private key, so when the data user and the cloud service provider conspire, the data user can use their own private key to re-encrypt The key is decrypted to obtain the sum of the data user's private key and the decryption noise, which is an approximation of the private key, so it cannot resist strong collusion attacks

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