The Research And Prototype Implementation Of Publicly Verifiable Computation

Outsourcing computing technology is one of the hot spots in modern cryptography research, its advantage is the weaker computing power equipment (such as mobile phones, netbooks, etc.) can outsource complex computation(such as image processing, complex function evaluation, etc.) to strong computing power equipment. The weaker equipment can get results from strong equipment. Outsourcing computing must satisfy the secrecy and verifiability. Secrecy means only the requester know the input and output, verifiability means the requester can verify the correctness of the computation results. For outsourcing computing technology, the cost of communication between server and requester, and verification complexity are important factors to measure a outsourcing computing solution.This paper introduces a Publicly Verifiable Outsourced-Computation model (PVOCM). Based on PVOCM, this paper designs a Publicly Verifiable Outsourced-Computation protocol with three communication entities, query party, compute party and source party. In this protocol, the query party and the compute party only transmit the variables,the function value and the proof which used to verify the function value so the overhead of communication costs are greatly reduced. Illustrated by the polynomial evaluation, the paper designs a Publicly Verifiable Outsourced-Computation solution based on bilinear pairing technology. The compute party uses polynomial decomposition theorem to construct evidence. The query party uses bilinear pairing technology in the verification process to ensure verification complexity is lower than computation complexity.Finally, this paper carries out a publicly verifiable outsourcing-computation prototype system. This system consists of three parties, source, server and client. Tests on this system show that the system guarantees that the client can accept the correct results and reject wrong results. These results show that this system has realized publicly verifiable outsourced-computation and high reliability for verification of results.