Multi-Matrix Verifiable Computation
This work addresses the need for efficient and secure computation outsourcing in cloud environments, representing an incremental improvement over existing methods.
The paper tackles the problem of securely outsourcing matrix function computations to cloud servers by proposing a multi-matrix verifiable computation scheme, which is roughly m times faster and has lower communication costs than the previous best scheme when outsourcing m linear functions.
The problem of securely outsourcing computation to cloud servers has attracted a large amount of attention in recent years. The verifiable computation of Gennaro, Gentry, Parno (Crypto'10) allows a client to verify the server's computation of a function with substantially less time than performing the outsourced computation from scratch. In a multi-function model (Parno, Raykova, Vaikuntanathan; TCC'12) of verifiable computation, the process of encoding function and the process of preparing input are decoupled such that any client can freely submit a computation request on its input, without having to generate an encoding of the function in advance. In this paper, we propose a multi-matrix verifiable computation scheme that allows the secure outsourcing of the matrix functions over a finite field. Our scheme is outsourceable. When it is used to outsource $m$ linear functions, the scheme is roughly $m$ times faster and has less communication cost than the previously best known scheme by Fiore and Gennaro (CCS'12), both in the client-side computation and in the server-side computation. We also show the cost saving with detailed implementations.