Paper 2009/547

Non-Interactive Verifiable Computing: Outsourcing Computation to Untrusted Workers

Rosario Gennaro, Craig Gentry, and Bryan Parno

Abstract

Verifiable Computation enables a computationally weak client to "outsource" the computation of a function F on various inputs x_1,...,x_k to one or more workers. The workers return the result of the function evaluation, e.g., y_i=F(x_i), as well as a proof that the computation of F was carried out correctly on the given value x_i. The verification of the proof should require substantially less computational effort than computing F(x_i) from scratch. We present a protocol that allows the worker to return a computationally-sound, non-interactive proof that can be verified in O(m) time, where m is the bit-length of the output of F. The protocol requires a one-time pre-processing stage by the client which takes O(|C|) time, where C is the smallest Boolean circuit computing F. Our scheme also provides input and output privacy for the client, meaning that the workers do not learn any information about the x_i or y_i values.

Note: Acknowledged two additional funding sources.