Efficient Proof Composition for Verifiable Computation

Outsourcing machine learning algorithms helps users to deal with large amounts of data without the need to develop the expertise required by these algorithms. Outsourcing however raises severe security issues due to potentially untrusted service providers. Verifiable computing (VC) tackles some of these issues by assuring computational integrity for an outsourced computation. In this paper, we design a VC protocol tailored to verify a sequence of operations for which no existing VC scheme is suitable to achieve realistic performance objective for the entire sequence. We thus suggest a technique to compose several specialized and efficient VC schemes with a general purpose VC protocol, like Parno et al.’s Pinocchio, by integrating the verification of the proofs generated by these specialized schemes as a function that is part of the sequence of operations verified using the general purpose scheme. The resulting scheme achieves the objectives of the general purpose scheme with increased efficiency for the prover. The scheme relies on the underlying cryptographic assumptions of the composed protocols for correctness and soundness.