Secure Multi-Party Computation on the Encrypted Network: a Lattice-based Multi-Party Homomorphic Encryption Protocol

With the continuous development of cloud computing technology and the increasing attention of privacy protection, users are not willing to disclose their private data, but also want to benefit from the results of a large number of data analysis. How to process multi-user privacy data in the cloud environment without disclosing personal privacy is an urgent problem that needs to be solved. Multi-Party homomorphic encryption supports the processing of the ciphertext data of different users, and the result of the processing can be decrypted jointly by all users involved in the calculation, which is more suitable for the privacy protection of multi-user data in the cloud environment. In this paper, we design a multi-party homomorphic encryption protocol with low communication complexity, no private channel restriction and users do not need to be online during ciphertext computation. The protocol mainly includes key generation algorithm and multiparty decryption algorithm based on secret sharing and homomorphic encryption, which improves the ciphertext computing capability of multi-user and multi-source data under different key encryption, and provides technical support for secure multi-party computing.