Research On Efficient CRT-Based Secure Multiparty Computation Scheme

With the development of data era,privacy-preserving computation has become a significant challenge on mobile devices.Secure multiparty computation plays an important role in more and more applications as a member of privacy-preserving techniques.Unfortunately,the existing secure multiparty computation schemes usually run on the computers with high computing power and high network bandwidth,which is inapplicable for mobile devices.To solve the problems mentioned above,we propose an efficient multiparty computation protocol secure against semi-honest adversary based on the Chinese Remainder Theorem(CRT)and re-encryption techniques.The concrete work of this paper is as follows.1.In this paper,we propose an efficient two-party computation protocol secure against semi-honest adversary.The scheme implements CRT-based homomorphic encryption and re-encryption techniques to support addition and multiplication operations over rings.In the concrete construction,one participant makes use of the re-encryption technology to unify the ciphertext encrypted by different private keys into the ciphertext encrypted by the same private key.The other participant makes use of the homomorphism of the ciphertext to perform the polynomial computation on the ciphertext.Finally,the calculation results can be obtained without disclosing the input privacy.Secondly,we prove that our scheme is secure against semi-honest adversary in the ideal-reality hybrid model.Finally,we analyze the feasibility of our scheme from both the perspective of theoretical complexity and the perspective of experiment.We select the state-of-the-art two-party computation scheme which is secure against the semi-honest adversary and compare the running time and communication overhead of two experiments under different bit length security parameters proving the high efficiency of our scheme.2.In this paper,we transform the two-party polynomial computation protocol to multi-party polynomial computation protocol for the semi-honest model.We present a concrete construction scheme for the three-party scenario.Firstly,all of the three parties re-encrypt their input into ciphertext encrypted by the private keys of two parties.Then the third party completes polynomial calculation.After the decryption by two participants,all three parties can fairly obtain the decrypted calculation results.In addition,we give the security analysis of the scheme.Finally,we select the state-of-the-art open source secure multiparty computation scheme and compare the running time and communication cost of the two schemes under different bit length security parameters proving the high efficiency of the scheme.3.Focusing on the problem that the existing secure multiparty computation protocols can not be implemented on low computing power and small memory space devices,this paper discusses the feasibility of running the secure computation scheme on mobile devices.In this paper,we present the concrete construction for privacy-preserving distance measurement in mobile applications and prove the feasibility of our scheme.