Verifiable ideal on-grid threshold proxy re-encryption method and verifiable ideal on-grid threshold proxy re-encryption system

Abstract

The invention belongs to the technical field of data encryption and privacy protection, and discloses a verifiable ideal on-grid threshold proxy re-encryption method and system, and the method comprises the following steps: generating a first public and private key and a second public and private key through a KeyGen algorithm; encrypting the original message according to the first public key to generate a ciphertext; generating an agent key through a ReKeyGen algorithm according to the first private key and the second public key, dividing the agent key into a plurality of key shares, and signing each key share through a homomorphic signature technology to obtain a plurality of key share signatures; converting the ciphertext into a plurality of ciphertext shares according to the pluralityof key shares, and converting the plurality of key share signatures into a plurality of ciphertext share signatures; verifying the legality of the corresponding ciphertext share according to each ciphertext share signature; combining the legal ciphertext shares into a re-encrypted ciphertext; decrypting the re-encrypted ciphertext according to the second private key to get the original message. According to the invention, the method and system have the advantages of high availability, low trust and strong security, can effectively resist quantum attacks, and is high in encryption efficiency.

Description

technical field [0001] The invention belongs to the technical field of data encryption and privacy protection, and relates to a verifiable threshold proxy re-encryption method and system on an ideal grid. Background technique [0002] Proxy Re-Encryption (PRE) is a conversion mechanism between ciphertexts. Without decryption, a semi-trusted agent converts the ciphertext of the authorizer into a ciphertext that can be decrypted by the authorized person. text, so as to realize encrypted message sharing. Proxy re-encryption is essentially the transformation of decryption authority. Therefore, the idea of ​​threshold is introduced into the proxy re-encryption system, and the re-encryption authority is split and entrusted to multiple nodes. Only when a certain number of nodes are satisfied with the re-encryption operation , to successfully complete the ciphertext conversion, which forms the threshold proxy re-encryption scheme (ThresholdProxy Re-Encryption, TPRE). TPRE can effe...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the disadvantages of the above-mentioned existing technology, which is based on the zero-knowledge proof method based on the discrete logarithm problem when verifying the ciphertext share, which cannot resist quantum attacks and has low efficiency, and provides a verifiable Ideal lattice threshold proxy re-encryption method and system

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