Verifiable Decryption Scheme Based on MLWE and MSIS
T he verifiable decryption technology involved in the two-party secure computing can be applied in real-world scenarios that require privacy protection,such as medical research data sharing,and inter-institutional cooperation for model training,which can help further break down the data isolation problem and ensure data security.However,the existing zero-knowledge proofs constructed for correct decryption based on lattice cryptography or other post-quantum encryption schemes are less efficient.Fa-cing this situation,this paper proposes a verifiable decryption scheme based on the module learning with errors(MLWE)and module short integer solution(MSIS)for Kyber.Firstly,based on the encryption and decryption properties of Kyber,there is a difference in constructing the equivalence relation using the data held by the prover and the verifier.The scheme proposes a me-thod that uses error estimation combined with Kyber compression function to enable the prover to provide the verifier with some information about his own data to eliminate the difference,and then provides an equivalence relation that can be used for verifica-tion,and combines this relation with the framework of the Dilithium signature scheme without public key compression version to construct a non-interactive zero-knowledge proof,which transforms the verifiable decryption problem into proving a linear relation satisfied by short vectors in the ring.Secondly,the correctness,security,communication overhead and computational complexity of the scheme are theoretically analyzed,the soundness and zero-knowledge of the scheme are reduced to the hardness assumptions of MSIS,and two groups of suggested parameters with different security levels are provided.Finally,the correctness and efficien-cy of this scheme are tested by writing a C program.Experimental results are consistent with the theoretical analysis results,and compared with the existing schemes,the scheme in this paper has significant advantages in terms of proof size and proof time for a single ciphertext,which is more concise and efficient.