In the digital world, so many copyrighted works are made in an illegal way because it is easy to keep and copy. Digital Rights Management has proposed to prevent this theft. Contents providers often bring in one server who has charge of managing the normal user, but there are some problems that it flocks to the server. Against this problem, P2P based DRM system has considered. All users can transfer the encrypted content to other users, so the content server does not have to load so much traffic from users. As a problem with this method, it is hard to figure out usage situation of contents because P2P based system is divided into many pieces of users. In this paper, we propose a new P2P based DRM system using Bitcoin protocol, which is one of the electric commerce. Bitcoin protocol, timestamp server saves all transactions to prevent double spending. We can bring out all usage situations to apply this system.
Open access
Digital Rights Management and Security
Advanced Steganography and Watermarking Techniques
Based on ELGamal digital signature and zero-knowledge proof with the method of directed signature,a two-way identification scheme was proposed,which enabled two specific users to validate each other's identity without exposing one's own secret information.The scheme has higher security and lower computing complexity.
This paper proposes a zero-knowledge proof scheme of possessing a DSA digital signature,in which the prover does not directly give the DSA signature of the message,but gives a zero-knowledge proof of possessing the DSA signature.Preventing the signature from being copied at discretion,the scheme can be used in copyright protection.
Recently we have observed a growing demand for secure technologies for e-commerce that do not put customers at risk of identity theft. We have also experienced the advent of Web 2.0 which has led to new business models and which has changed the way users interact with the Web. This thesis proposes a set of strategies and enhancements towards providing improved security and privacy in such new settings. We introduce a novel concept: Fair Rights Management (FRM). It can be classified as a usage control solution. FRM enables a flexible way of managing digital content. There was a need to provide additional security extensions to keep such a flexible model applicable. Thus, in our approach we take advantage of trust obtained from social networks. This is also the reason why we created an efficient zero-knowledge proof protocol that is lightweight enough to be deployed within existing web-applications. The proposed protocol is also successfully integrated with Semantic Web architecture and associated components. It enables practical Web and mobile applications which employ trust-based transactions as part of their workflow. This core contribution overcomes various disadvantages of prior art and enables a range of new applications and potentially new business models. We show that compared to existing Usage Control Models (UCON) (i) FRM is a step towards fair use in the digital world and we also argue that our approach is enforced by law; (ii) the participants of the proposed solution do not put their privacy at risk. Our research shows that existing infrastructure is sufficient to support ZKP-based solutions; and thus, it is feasible to offer the users enhanced privacy within existing deployed solutions.
Aiming at the problem that current schemes can not protect the benefits of proxy signer and message owner at the same time,this paper presents a blind proxy blind signature scheme on elliptic curve. By using Elliptic Curve Cryptography(ECC) and zero-knowledge proof,it has small amount of computing,high security and high implementation efficiency. Security analysis proves that the scheme satisfies the security properties of blind proxy signature scheme and proxy blind signature scheme,and it has strong enforceability.
In order to solve the security problem that the E-cash users get from bank have no blindness in the new E-cash system based on partial blind signature,this paper brings forward a new E-cash payment model which combines zero-knowledge identity proof based on improved ELGamal signature and partial blind signature. It can track user with the help of the third trusted party to avoid using E-cash illegally. Security analysis indicate that the model has strong security and practicability.
The similarity of E-cash and E-lottery was taken into account to have designed a secure E-cash-lottery scheme by using zero-knowledge proof and blind signature on the basis of applications of the traditional lottery. This E-cash-lottery is characterized with anonymity, double stake resisting, forgery resisting, traceableness and off-line. For lottery players, banks, and lottery delivery to infer the identity of the winners by E-lottery is as difficult as for them to solve discrete logarithm. For lottery players to forge the E-cash or the E-cash-lottery is as difficult as for them to attack the RSA public key signature system. If there exists any repeated spending by using this E-cash- lottery, the bank can certainly determine the identity of the spender. Compared with the traditional lottery, the anonymity and privacy of the E-cash-lottery were preferable.
Advanced Steganography and Watermarking Techniques
A secure web-based watermarking scheme is proposed to allow the publisher or information provider to mark their copyrighted materials and identify an illegal distributor through the World Wide Web (WWW). In our proposed scheme, multi-watermark techniques and double encryption method is applied to make the scheme available in e-transaction and secure against collusion attacks even if the third party is not trusted. And the basic idea of zero knowledge proof is also used to make verification of an illegal distributor without the disclosure of any watermark information. Furthermore, a multiparty transaction scenario is also introduced by using our scheme in this paper. The analysis results indicate that our design goals are successfully achieved and some improvements are made over previously proposed schemes.
Advanced Steganography and Watermarking Techniques
As its own security risks of existing patent trading platform, on-line patent transaction can not be realized. The security problems are mainly embodied in the confidentiality of transaction information, and security of patent delivery areas. One of the important characteristics of zero-knowledge proof is zero-knowledge, which can enable the verifier to believe that the conclusion is correct without knowing the contents of it. This characteristic can solve the problems of current patent transaction security mentioned above. Based on zero-knowledge proof, through the framework and flow design, this paper builds a secure patent trading platform, which shows a new way of patent trading. What is more, the security and convenience of this trading platform are better than ever before.
To increase the flexibility of proxy divisible E-cash system and decrease its communication and computational complexity,and to revoke proxy power after finite warrant period,a new proxy divisible E-cash system based on discrete logarithm proxy signature and discrete logarithm zero knowledge proof is presented.The new scheme satisfies non-forgeability,nonrepeatability,coin tracing and owner tracing that common E-cash possess security requirement.Finally,compared with divisible E-cash system based on 2-node tree partition method,the study shows that the new scheme is based simple subtration partition method and has high efficiency and low communication.
A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyer's watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.
Advanced Steganography and Watermarking Techniques
A non-interactive zero-knowledge proof protocol based on Elliptic Curve Encryption was proposed,and based this protocol,a publicly verified secret sharing scheme was proposed too.In the scheme,secret and secret shadow were embedded onto the points of Elliptic Curve,anybody can verify them publicly,and only the legitimate participants set can recover the secret key,but knowing nothing about the secret key.This scheme can prevent adversaries from getting the secret,the dealer from distributing improper data and the participants from cheating each other efficiently.Furthermore, it is propitious for the replication and update of secret.
Based on USB key and zero-knowledge proof,a mutual authentication scheme is proposed in this paper,which has realized to user’s authentication,moreover has realized to user’s public key authentication.The analysis indicates that the scheme is secure and the computation complexity is low.
This paper proposes RSA-based zero-knowledge proof watermark verification protocols.It can tackle the problem of disclosing sensitive information.In the protocols,the public key encryption are used to encrypt the watermark and the watermarked data of the watermark embedding locations,the open verification of copyright watermarking is achieved through estimating the relativity of them.Furthermore,the authors research how to resist cheat-attack,and propose the way that prover and verifier can only communicate with each other to resist this attack.
Advanced Steganography and Watermarking Techniques
Both knap sack problem and discrete logarithm problem are difficultly solved.This paper proposes a digital signature scheme based on the property of knap sack problem and elliptic curve public-key cryptosystem.The modified scheme can also be used in zero-knowledge proof,and has high security and reliability in practice.
To prevent e-cash from double-spending and unlimited increase in the records of databases,an improved offline e-cash system based on elliptic curve cryptography was proposed.The improved system utilizes good properties of elliptic curve cryptography system and adopts zero knowledge proof.Partial blind signature based on elliptic curve cryptography ensures that the e-cash is valid only in the period issued by the bank according to the withdrawal protocol,and the historical record of the e-cash that exceeds the valid period will be removed,which greatly reduce the amount of traffic and effort of calculation and improve the efficiency.The security of the system was improved by adopting the elliptic curve zero knowledge proof in the payment protocol.
A non-interactive publicly verifiable protocol based on the intractable problems of discrete logarithm in elliptic curves cryptography is proposed.A non-interactive publicly verifiable zero knowledge proof protocol is designed.A new non-interactive publicly verifiable electronic voting scheme is established.This scheme enables anybody to verify if the shares are correctly distributed.This scheme can protect against the cheating action and is applicable to elections of smaller scale.
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
There exist some drawbacks such as quite deep binary tree and the linkability within various nodes from the same ancestor in the divisible electronic cash (e-cash) scheme based on quadratic residuosity problem. Based on signa- tures of zero-knowledge proof and strong RSA problem, the concept of group signature was firstly introduced to off-line divisible e-cash thereafter, a new off-line divisible e-cash payment system was presented. In the new system, the ancestor node could be divided into more than 2 nodes, and above all, different nodes stem from the same e-cash was unlikable.
Access Control is an important mechanism of information security. Role-Based Access Control is a famous access control approach with good flexibility. RBAC96 and ARBAC97 are classical RBAC models. The ARBAC97 model facilitates decentralized administration of RBAC. However, ARBAC97 has some shortcomings in the case of being used in an organization with autonomous subsidiaries. The member of an administrative role can operate directly in the role range of a junior administrative role, which violates the autonomy of subsidiaries. We propose a new model named N-RBAC to overcome this weakness. In N-RBAC, roles are arranged according to a hierarchical namespace structure. Thus the role hierarchy is constructed in a local space instead of in a global space. The N-RBAC model does a better work in decentralized role administration in those organizations composed of autonomous subsidiaries.
As Jack Black's character in the recent movie School of Rock instills in his young charges, “[I]n this life you can't win… because the world is run by the man… there used to be a way to stick it to the man, it was called rock'n roll… but guess what, oh no the man ruined that too with a little thing called MTV.” View MTV as the epitome of everything that is wrong with the music industry and you pretty much have the essence of the philosophical-musical dichotomy between how the industry and consumers each perceive the state of music. Jack Black's character, who poses as a substitute teacher at an elite preparatory elementary school, further admonishes his students: “If you want to rock, you gotta break the rules, you gotta get mad at the man.” One battle in the war between the “downloaders” (consumers) and the industry (the “man”) came to a head in the long-awaited decision in Metro-Goldwyn-Mayer Studios Inc. v. Grokster, Ltd. The decision offers several important lessons for those with some stake or interest in the continued battle between copyright owners and copyright users - or abusers. This article, the first of two, discusses the background legal principles and surrounding case law involved in Grokster and proceeds to review the holding of the decision and the facts on which it was based. A later article will discuss a possible “safe harbor” for fair use and the potential impact of the ruling on future Internet technologies and on various stakeholders. Most readers are aware of the concept of copyright infringement. In recent years one could hardly escape discussion of it, especially in light of the publicity that lawsuits against individual file-sharers generated in the national media. Philosophers among us might think such strong-arm techniques against un-named defendants are unethical or at least that responsibility for wrongdoing ought to be shared with those who facilitate infringement and not the end-user alone. Likewise, economists among the Bulletin's readership might wonder if the transaction cost of pursuing remedy from some 12-year-old downloader or a college student struggling to make ends meet is further proof of the market failure inherent in the copyright law. Actually, the copyright law reflects these same sorts of quandaries. The concept of secondary liability, in particular contributory infringement, reflects the judicial recognition that at times a third party should share in the responsibility for another's primary or direct infringement and that pursuit of these actors is a fair and efficient form of risk-shifting within the law. While the concept is well developed in the lower courts, and one could argue that a version is codified in the Copyright Act as amended (17 U.S.C.§ 512) in 1998 by the Digital Millennium Copyright Act, the concept remains a product of the common law. In addition, the Supreme Court has had little occasion to address the matter of secondary liability. New technologies have twice presented opportunities for the Court to consider the matter - first in 1984 and some 20 years later this past spring (oral arguments were heard in March) and summer. In 1984 it was the videocassette recorder (in Sony Corp. of America, Inc. v. Universal City Studios), and in 2005 it was P2P or peer-to-peer file sharing systems in Metro-Goldwyn-Mayer Studios Inc. v. Grokster, Ltd. a degree of knowledge that makes a person legally responsible for the consequences of his or her act or omission; the fact of an act's having been done knowingly, especially as a ground for civil damages or criminal punishment - p. 1373. As a result, a claim of contributory infringement contains an element of knowledge; that is, the contributing or contributory infringer must know or have reason to know that the infringing behavior of another will be the result of its conduct. This requirement ensures that accidental or ignorant conduct is not mistaken for bad intent. Second, a contributory infringer must engage in conduct that contributes to the direct infringement of another person in some substantive way, by doing something or in some circumstances by refusing to do something (for example, not intervening to prevent continuing infringement). As with vicarious liability (another species of secondary liability), if there is no direct infringement there can be no contributory liability. Under the Sony standard, adopted from the patent law's staple article-of-commerce doctrine, the Supreme Court in 1984 created a safe harbor for entrepreneurs: simply because a product could be put to infringing use, the conduct of producing and distributing the product (or refusing to cease such operations) did not trigger liability as long as the technology could be capable of substantial non-infringing use. Moreover in a somewhat clairvoyant and telling footnote the Sony dissent observed that “[t]his case involves only the home recording for home use of television programs broadcast free over the airwaves. No issue is raised concerning cable or pay television, or the sharing or trading of tapes” [Sony Corp. of America, Inc. v. Universal City Studios, 464 U.S. 417, 459, n.2 (1984) (J. Blackmun, dissenting) (emphasis added)]. Thus the fair use the Supreme Court bored out in 1984 for consumers came in the form of time-shifting, not in the guise of all consumer recording such as library-building, back-up copying or transferring formats from cassette to CD or from CD to MP3 - so-called space-shifting. In other words the protections of Sony's safe harbor for substantial non-infringing use do not apply in instances where the questionable activity involves the use (reproduction and distribution) of copyrighted content obtained from sources other than those offered for free through various mass media such as radio (but not feebased Internet services) or broadcast television (as opposed to cable or satellite). In other words it applies where the facts of Sony apply – to consumers using the recording technology to tape movies and other content that air on broadcast television networks such as NBC, CBS and PBS. Networks are not the source of most P2P content where much of the source content is recorded music (CD) or movies (VHS or DVD) first purchased by the consumer. Moreover, the copying done by the Sony consumer is one-to-one, not one-to-many. Most important, the use of the technology in Sony was limited to circumstances where consumers made a limited, time-shifted use of the copyrighted work, one of the most misunderstood aspects of the decision. Thus, obtaining CDs, VHS tapes or DVDs from your local public library - a free distribution authorized under section 109 of the copyright law - in order to build a library at home would not be within the Sony safe harbor, at least according to one appellate court (In Re Aimster Copyright Litigation, 334 F.3d 643, 647 (7th Cir. 2003)). The Sony Court discussed the nature of the alleged contributory technology: some uses to which the technology, the Beta machine, could be put were conceivably infringing, so-called “library building” for example, but others were fair, e.g., a consumer might buy or rent a video or watch a home movie of family outings. In other words, a substantial number of non-infringing uses were possible. Therefore the Beta machine, like the VHS recorder of today, is not a contributory technology (Sony Corp. of America, Inc. v. Universal City Studios, 464 U.S. 417, 442 (1984)). In 1984, the Court used this distinction to develop a test to help courts determine whether a certain technology contributes to the infringement of others to such an extent that its producers should be deemed to have engaged in contributory conduct and share in the legal responsibility for infringing uses others make of it, that is, be liable for contributory copyright infringement. The question for the Court in Grokster was whether P2P is such a technology as well. [e]ven when there are non-infringing uses of an Internet file-sharing service, moreover, if the infringing uses are substantial then to avoid liability as a contributory infringer the provider of the services must show that it would have been disproportionately costly for him to eliminate or at least reduce substantially the infringing uses. - In Re Aimster Copyright Litigation, 334 F.3d 643, 653 (7th Cir. 2003) (all emphasis added). How this factor is to be applied is not further elucidated by the court, nor is the attractiveness of this standard to courts outside the Seventh Circuit determinable. However, Justice Ginsburg in her concurring opinion cited this cost-benefit concept in a favorable comparison to the decision in A&M Records, Inc. v. Napster, Inc., [Metro-Goldwyn-Mayer Studios Inc. v. Grokste, Ltd., __ U.S. __, 125 S.Ct. 2764, 2784, at n.1 (2005) (Ginsburg, J., concurring)] in which the Ninth Circuit offered an alternative articulation of the legal standard applicable in P2P litigation [A&M Records, Inc. v. Napster, Inc., 239 F.3d 1004 (9th Cir. 2001)]. We are mindful that the Seventh Circuit has read Sony's substantial non-infringing use standard differently… However, Aimster is premised specifically on a fundamental disagreement with Napster 1's reading of Sony-Betamax… Even if we were free to do so [entailing an overrule of Napster] we do not read Sony-Betamax's holding as narrowly as does the Seventh Circuit…Implicit in the Aimster analysis is that a finding of substantial non-infringing use, including potential use, would be fatal to a contributory infringement claim, regardless of the level of knowledge possessed by the defendant. - Metro-Goldwin Studios, Inc. v Grokster, Ltd., 380 F.3d 1154, 1162, at n. 9 (9th Cir. 2004), reversed and remanded, __ U.S. __, 125 S.Ct. 2764 (2005). In June of 2005, the U.S. Supreme Court in a unanimous decision authored by Justice Souter (with concurrences by Justices Ginsburg and Breyer) held “that one who distributes a device with the object of promoting its use to infringe copyright, as shown by clear expression or other affirmative steps taken to foster infringement, is liable for the resulting acts of infringement by third parties” [Metro-Goldwyn-Mayer Studios Inc. v. Grokster, Ltd., — U.S. —, 125 S.Ct. 2764, 2770 (2005)]. The question before the Court was “under what circumstances the distributor of a product capable of both lawful and unlawful use is liable for acts of copyright infringement by third parties using the product.” While it might appear at first glance that the opinion represents a retrenchment from Sony, it is clear from Justice Souter's opinion that the rule and safe harbor of Sony remains the law of the land. However, the Court did identify an additional mode of behavior that can subject an entrepreneur to liability as a contributory infringer. This addition is significant and offers some indication of how the Court might respond when future issues arise. In an interpretation of nuance, the decision may also signal the proper judicial attitude toward Internet piracy today. Liability under our jurisprudence may be predicated on actively encouraging (or inducing) infringement through specific acts (as the Court's opinion develops) or on distributing a product distributees use to infringe copyrights, if the product is not capable of “substantial” or “commercially significant” non-infringing uses. - (Ginsburg, J., concurring) The intended impact will be to “deter them [entrepreneurs] from distributing products that have no other real function than - or that are specifically intended for - copyright infringement, deterrence that the Court's holding today reinforces (by adding a weapon to the copyright holder's legal arsenal).” (Breyer, J., concurring) This is the first point of significance in the opinion. The Court is more than willing to fashion a remedy if it believes a wrong must be righted. Moreover, the Court may look to other regimes within the intellectual property system, even if it means creating a new form of liability, such as borrowing again from the patent law. Not only can one induce infringement with respect to conduct in relation to a particular consumer (the previous articulation of contributory conduct developed in the lower courts) but the mere “distribution of a product can itself give rise to liability where evidence shows that the distributor intended and encouraged the product to be used to infringe. In such a case, the culpable act is not merely the encouragement of infringement but also the distribution of the tool intended for infringing use.” While Sony involved distribution of a product to be sure, the additional element of inducement was absent. As a result of the Court's opinion, the Ninth Circuit decision in the Grokster case was vacated and remanded for further proceedings. The immediate significance is that Grokster and StreamCast (the two defendants in the case), as well as other similarly situated defendants, may be subject to secondary liability for copyright infringement if those defendants “distribute a device with the object of promoting its use to infringe copyright, as shown by clear expression or other affirmative steps taken to foster infringement, [if supported by the evidence, the defendant] is liable for the resulting acts of infringement by third parties.” Figuring the impact of this ruling requires a closer look at the opinion, examining what the Court said as well as what the Court left unsaid! But MGM's evidence gives reason to think that the vast majority of users' downloads are acts of infringement, and because well over 100 million copies of the software in question are known to have been downloaded, and billions of files are shared across the Fast Track and Gnutella networks each month, the probable scope of copyright infringement is staggering. The evidence weighed heavily against the defendants and the infringing nature of most downloading and uploading. In fact Grokster and StreamCast conceded this point in their brief. Moreover, internal documentary evidence (there's always a memo) suggested that both Grokster and StreamCast desired to fill the empty shoes Napster left behind, exploiting the extant market for users desiring a vehicle to continue their infringing quests for copyrighted recordings and other material. Advertisements and other external communications reflected the outward expression of this internal desire. The Court appeared less concerned with the fact that some amount of non-infringing material appeared on Grokster and StreamCast systems (or P2P systems in general for that matter) or that this material is put to non-infringing uses. Of greater concern was the fact that this non-infringing material accounts for very little of the actual use made of the available material. The Court was not persuaded by arguments that Grokster, StreamCast and similar P2P systems are widely put to legitimate uses; indeed, the court recognized, as have lower courts, the sheer scale of piracy facilitated through digital and Internet technologies. Here, there has been no finding of any fair use and little beyond anecdotal evidence of non-infringing uses. In finding the Grokster and StreamCast software products capable of substantial non-infringing uses, the District Court and the Court of Appeals appear to have relied largely on declarations submitted by the defendants. These declarations include assertions (some of them hearsay) that a number of copyright owners authorize distribution of their works on the Internet and that some public domain material is available through peer-to-peer networks including those accessed through Grokster's and StreamCast's software. - (Ginsburg, J., concurring) Nor does the Patent Act's exemption from liability for those who distribute a staple article of commerce, extend to those who induce patent infringement, § 271(b). But nothing in Sony requires courts to ignore evidence of intent if there is such evidence, and the case was never meant to foreclose rules of fault-based liability derived from the common law… Thus, where evidence goes beyond a product's characteristics or the knowledge that it may be put to infringing uses, and shows statements or actions directed to promoting infringement, Sony's staple-article rule will not preclude liability. This finding is the second significant point that can be made. The Supreme Court appears unmoved by the mere possibility of non-infringing uses and more influenced by the improbability of such uses. It might be going too far to conclude that the Court is as disdainful of Internet piracy as some recent lower courts have been [In Re Aimster Copyright Litigation, 334 F.3d 643, 645 (7th Cir. 2003); United States v. Elcom Ltd., 203 F.Supp. 2d 1111, 1132 (N.D. Cal. 2002)], but the interjection of such sarcasm does suggest that claims of non-infringing uses from subsequent defendants will be suspect. Legitimate uses will need to be well documented. The Court, like others in positions of policy formation, such as Congress, appear to recognize all too well the scope of the problem in spite of perhaps grasping only the proverbial elephant's trunk. If some readers here are in doubt regarding the extent of piracy on the Internet, do the math as did the Court: “over 100 million copies of the software known to have been downloaded” times the “billions of files shared across the Fastrack and Gnutella networks each month” equals a figure reflecting that “the probable scope of copyright infringement is staggering.” Factor in the variety of other P2P systems capable of similar exchanges, such as intranets, and the amount of infringing traffic is more likely astronomical. Regardless of the actual numbers, the perception of members of the judiciary reflected in court opinion as well as expressed by members of Congress paints a view of decision-makers short on patience and long on punishment. For example, after holding hearings in 2003 on the P2P rampage and other copyright abuse among student Internet users [see <http://commdocs.house.gov/committees/judiciary/hju85286.000/hju85286_0.htm> and <http://hsgac.senate.gov/index.cfm?Fuseaction=Hearings.Detail&HearingID=120>], legislation was introduced that would offer plaintiffs the opportunity to sue those who aid or abet another's infringement [S. 2560, 108th Cong., 2nd Sess. (2004) (Inducing Infringement of Copyright Act of 2004)]. What do these attitudes and the new law spawned in Grokster represent for the future of innovation in Internet technologies? Perhaps we must wait to see how the lower courts interpret Grokster before the decision's full impact can be assessed, and, of course, Congress might decide to tinker again with the copyright law. Several additional comments from the decision, however, may point to the basis for such future articulation, and we will explore them in Part 2 of this article.
Most e-cash systems have anonymity to protect users' privacy, but few of them provide the non-repudiation service such that many problems such as blackmailing , money laundering , losing, misusing and double-spending can been avoided. Based on the partial blind digital signature and zero-knowledge proof,an e-cash system with non-repudiation is constructed in the article.
On the base of home researching the idea of the proxy si gnature a kind of algorithm of the zero knowledge proof is proposed based on proxy signature in this paper. This algorithm has characteristics which are simple and easy to be realized.