Fair E-payment Protocol Based On Partially Blind Signature

With the development of information technology, Message is playing a more andmore important role in the society.Information not only changes the ways of people’slife and work but also becomes the core of modern society.So information securityis becoming more and more important,and cryptography is what people concern.Aiming at the intrinsic problems in partially blind signatures, such as reducingcomputation costs, shortening signature length and so on, a new partially blindsignature scheme is proposed based on Schnorr blind signature scheme. Comparedwith the previous schemes, the proposed scheme is more efficient. The exponentiationnumber is reduced from8to5and the multiplication number is reduced from8to4,the size of a signature is shortened|q|where q is the order of the underlying group.Under random oracle model and generic group model as well as ROS assumption, theproposed scheme is provably secure.Then, a fair e-payment protocol is given by conversely using the proposedpartially blind signature. An advantage of this protocol is that two participants achievethe goals of exchanging their signatures without intervention of a third party. The lowcomputations and good properties of the underlying partially blind signatureguarantee that the proposed protocol has needed efficiency and security.