Verifiable delegation of computations with storage-verification trade-off

Abstract

Outsourcing computations has attracted much attention in recent years. An important security challenge is ensuring the correctness of the computed results. In the Verifiable computation (VC) model of Gennaro, Gentry and Parno (CRYPTO 2010), a client can delegate the computation of its function to a cloud server, and efficiently verify the correctness of any computed results. In the existing VC schemes, the server must store an encoding of the function that doubles the required cloud storage, compared with storing the function itself. In this paper, we introduce a parameter that measures the trade-off between the required cloud storage and the client's verification time. We construct four (privately or publicly) VC schemes for delegating polynomials and matrices. These schemes allow the client to significantly reduce the consumed cloud storage by slightly increasing its verification time. © 2014 Springer International Publishing Switzerland.