Research And Implementation Of Publicly Verifiable Computation Based On Revocable KPABE

Smart phones,tablet computers and other small and convenient mobile devices provide a lot of convenience for people's life,but these devices cannot quickly and efficiently solve some complex computing tasks.At this point,the outsourcing computation provides people with more choices.However,only the results cannot satisfy people's needs,people also want to verify the correctness of the results.Verifiable computation service will solve this problem to some extent.Among them,the publicly verifiable computation has better universal applicability,and becomes the better choice.But most of the researches about publicly verifiable computation focus on the verification of the results,and there is no any measure for misbehaving servers.Those servers can continue to provide invalid computation for other clients,which greatly wastes resources.Therefore,in this work,we study the publicly verifiable computation with revocation capability which is needed in the practical application environment,to ensure clients get correct results timely and effectively,and the misbehaving server will receive corresponding punishment at the same time.For most of the verifiable computation schemes not supporting revocation service,in this paper,we apply revocable KPABE to publicly verifiable computation,and construct a revocable publicly verifiable computation model.The KPABE can proof that the Boolean function is true,and revocable KPABE can provide a way of revocation entity.At first,we make formal definition of the system model,and give eight basic algorithms and security model.Then we design four security experiments for different security requirements,and define the security.Combined with bilinear pairing,digital signature,access structure,secret sharing and other technologies,we design and detailed descript a revocable publicly verifiable computation scheme.Security analysis shows that the scheme has security features such as publicity,revocability,blind verifiability and identity unforgeability.Finally,based on the KPABE scheme of our thesis,we design and implement a revocable publicly verifiable computation prototype system.The system involves three party entities,that is,a key distribution center,clients and servers.We design the functions and classes for these three parties.System includes functions of initialization,server registration,server authentication,outsourcing computation,verification results,revocation server and so on.Not only has the common functions of the publicly verifiable computation,but also can revoke the misbehaving server,so that it cannot perform the later computation.We test the above functions and verify the availability,and the experimental results show that the system is feasible in practice.The publicly verifiable computation with revocation has wider application prospects and practical significance.