Secure and Efficient Protocol for Outsourcing Large-Scale Matrix Multiplication to the Cloud

Outsourcing computing is an application of cloud computing. It is an important method to solve the problem of client resource limitation. However, outsourcing computing brings security and efficiency challenges. Matrix multiplication computation (MMC) outsourcing has attracted many researchers to carry out research and has achieved many admirable results. Unfortunately, there is still a problem with zero elements of information protection for MMC outsourcing. In this paper, we are motivated to design a protocol, which can protect the private information of the zero elements, for outsourcing MMC to the cloud server. Our proposed protocol not only solves the problem of protecting zero elements information but also has no large client-overhead. The main idea is to add a special matrix to the original matrix for hiding zero elements before transforming the computation task. Then, the cloud server computes the received encryption task and returns the result to the client. Finally, the client decrypts and verifies the result. The experiment verifies the efficiency and practicability of our protocol. The comparison with previous schemes shows that the protocol improves security without much client overhead.