Design of an efficient verification scheme for correctness of outsourced computations in cloud computing

Abstract

As cloud computing allows consumers or clients to store and delegate their sensitive data, cloud service providers have a lot of power over this data. Hence, the service providers in cloud computing cannot be trusted. To protect itself from being cheated on, by the untrusted service provider, the client needs a way to verify the correctness of computations returned by the cloud server, on its own machine. This should have very low computational cost as compared to the original computational cost of the outsourced computations. Operation on vectors is one of the major computations performed by cloud servers as many applications hosted on it use vectors. One of the major operations on vectors is calculating the inner product of the vector and matrix multiplication extensively uses inner products. In this work, we present an efficient algorithm to verify the correctness of inner products of vectors, on the client side. Also, we efficiently apply this scheme to verify the product of matrices. We also present an extensive security analysis and prove mathematically that, the client can verify the correctness of the computations, with a significant probability of success. We also demonstrate the efficiency and correctness of the proposed algorithm.