Multi-server verifiable delegation of computations: Unconditional security and practical efficiency

Outsourcing computation has gained significant popularity in recent years due to the prevalence of cloud computing. There are two main security concerns outsourcing computation: how guarantee server performs correctly and keep client's data secret. The single-server verifiable (SSVC) Gennaro, Gentry Parno (Crypto'10) enables a client delegate function f on any input x with both highly relieved, but only results computationally secure schemes that lack practical efficiency. While SSVC use single server, this paper we develop multi-server (MSVC) model where shares among multiple servers, each set computations its shares, finally reconstructs f(x) from all servers' results. In MSVC propose generic construction for form Fx, F is matrix vector. Our achieves information-theoretic security, privacy privacy. By optimizing parameters, obtain 3-server scheme, which uses least number 4-server incurs workload. decomposing many polynomial as two-stage computation, first-stage Fx second-stage fast, delegating these polynomials. We implement our show they most ones date.