Cash Scheme Research Articles

TOMIN: Trustworthy Mobile Cash with Expiration-date Attached

Online mobile payment systems based on mobile cash provide privacy to customers and are feasible for real point of sale, virtual point of sale, and person-to-person mobile commerce scenarios. The merchant does not perform complex operations and the bank verifies the validity of the mobile cash before the merchant delivers the product. The bank must store the mobile cash spent in a database to prevent a double spending attack. In this paper, we propose an efficient mobile cash scheme in which the customer attaches the expiration date and deposit date. This property reduces the size of the bank’s database and the customer must spend the mobile cash before expiry. Moreover, the customer attaches the merchant’s identity into the mobile cash in the deposit phase. The scheme requires low computational cost and is suitable for mobile devices

Foreword of Special Issue on “Information Education and Technological Application”

Foreword of Special Issue on “Information Education and Technological Application”

Optimized Electronic Cash Scheme with Fast Public Key Algorithm

In the paper, we analyzed the system optimization algorithms in e-cash (electronic cash) by improving the efficiency of e-cash for software and hardware application. As for the fast asymmetric cryptography algorithms in e-cash scheme, we presented basic interactive protocols based on discrete logarithm cryptosystem. In the protocol, the interacting algorithms achieve authenticated encryption in secret transmission algorithms, the verification of signature and transmission of secret message can be fulfilled in a single algorithm, and therefore the complexity of authentication algorithms in e-cash scheme is greatly reduced. As a comparison with traditional e-cash schemes, we presented an optimized e-cash scheme based on ECC (Elliptic Curves Cryptosystem). The cryptography algorithms of the scheme make full use of the superiority of ECC fast algorithms, thus the optimized e-cash scheme effectively avoids illegal distribution of e-cash and generalized forgery attack on system parameters with less system overheads.

Distributed architectures for electronic cash schemes: a survey1

The volume of E-commerce transactions has considerably increased in the last several years. One of the most important aspects of such progress is the efforts made to develop and deploy dependable and secure payment infrastructures. Among these infrastructures is electronic cash, which is an attempt to reproduce the characteristics of paper cash in online transactions. Electronic cash schemes have so far been the purpose of a significant amount of research work. Although real-life deployments of such schemes are expected to take place in highly distributed environments, limited attention has been paid in the literature on underlying architectural issues. So far the focus has mostly been on addressing only security issues. However, for real-life deployment, distributed processing criteria such as performance, scalability and availability are of prime importance. In this paper, through a survey of the literature, we identify and analyse the different distributed architectural styles underlying existing e-cash schemes. We discuss the strengths and limitations of these architectures with respect to fundamental system distribution criteria. In light of such discussion, we make some recommendations for designing effective distributed e-cash systems from an architectural perspective.

Research on transferable off-line electronic cash system

In this paper, a new cash scheme is proposed for electronic payment system, in which the cash can be transferred several times. When this kind of cash is used, the fraud such as double spending can be found out but the bank and the trusted party needs not be involved online in each transaction. This cash system is anonymous in normal transactions. But if a fraud happens, the trusted party can withdraw the anonymity to find out the cheater. The new cash scheme is transferable, anonymous, off-line and efficient.

Long‐term Care Policies in Italy, Austria and France: Variations in Cash‐for‐Care Schemes

Abstract Cash benefit provisions have been at the core of many recent reforms in the long‐term care sector in Europe. The respective schemes, however, vary widely in terms of the definition of entitlements, the level of benefits, and the ways in which benefits can be used by recipients. This article investigates cash‐for‐care schemes in three European social insurance countries. It asks whether the diversity of these schemes indicates different paths or just differences in the pace with which the respective policies address the risk of dependency. A characterization of the three schemes and a discussion of the implications for care work arrangements lead to the conclusion that the context and timing of long‐term care reform processes are in fact quite variegated. All three countries have histories of cash schemes and of applying the cash approach to support – and to some extent relieve – traditionally strong family obligations. Differences predominate in terms of linking cash to employment, although some convergence is apparent in the effects on qualifications, working conditions and wages in care work.

ID-Based Fair Off-Line Electronic Cash System with Multiple Banks

ID-based public key cryptography (ID-PKC) has many advantages over certificate-based public key cryptography (CA-PKC), and has drawn researchers' extensive attention in recent years. However, the existing electronic cash schemes are constructed under CA-PKC, and there seems no electronic cash scheme under ID-PKC up to now to the best of our knowledge. It is important to study how to construct electronic cash schemes based on ID-PKC from views on both practical perspective and pure research issue. In this paper, we present a simpler and provably secure ID-based restrictive partially blind signature (RPBS), and then propose an ID-based fair off-line electronic cash (ID-FOLC) scheme with multiple banks based on the proposed ID-based RPBS. The proposed ID-FOLC scheme with multiple banks is more efficient than existing electronic cash schemes with multiple banks based on group blind signature.

Provably Secure Untraceable Electronic Cash against Insider Attacks

Although a great deal of research has been done on electronic cash schemes with blind multisignatures to prevent an insider attack, there is no discussion of a formal security model in the literature. Firstly we discussed the security model of e-cash schemes based on the blind multisignature scheme against a (restricted) attack model and proposed a concrete scheme proven to be secure in the model [1]; however, this attack model disallows an attacker from corrupting an issuing bank and shops in the forgery game. In this paper, first, we reconsider the security model to remove the restriction of the attack model. Second, we propose a new untraceable e-cash scheme with a blind multisignature scheme and prove that the proposed scheme is secure against the (non-restricted) attacks under the DDH assumption in the random oracle model.

An Electronic Cash System Based on Group Blind Signatures

One important requirement of electronic cash systems is the anonymity of customers. Unconditional anonymity is also very well suited to support criminals in blackmailing. Maitland and Boyd proposed at ICICS 2001 an offline electronic cash system based on a group signature scheme. Their scheme cannot be used to solve blackmailing and other anonymity problems such as money laundering and illegal purchases. Chen, Zhang and Wang suggested an offline electronic cash scheme to prevent blackmailing by using the group blind signature. In their payment system, they used a group signature scheme of Camenisch and Stadler for large groups which is not secure. In this paper we improve these electronic cash systems to prevent blackmailing, money laundering and illegal purchases by using a secure coalition-resistant group blind signature scheme.

Research on the validity duration of off-line E-cash

To solve the drawback of the present electionic cash (E-cash) schemes that the size of bank's transcripts database expands without bound, the concept of validity duration of E-cash is introduced in this paper. Through improving the users' blind transforms of Brands' scheme, we design an efficient off-line E-cash system based on the restrictive blind signature and representation problem. The security analysis shows that the users can not forge a valid electronic coin or double spend it, in addition, the bank can not trace an honest users' payment behaviours. In compare with Brand's scheme, our scheme reduces storage costs and computation overhead of the users and the banks. Most of all, the electronic cashes will be authorized within a limit period only, the size of bank's transcripts database becomes controllable.

An Electronic Cash Scheme and its Management

A secure electronic cash scheme and its role-based access control (RBAC) management are proposed in this paper. The scheme uses electronic cash for payment transactions. In this protocol, from the viewpoint of banks, consumers can improve anonymity if they are worried about disclosure of their identities. A new role called anonymity provider agent (AP) provides a highly anonymous certificate for consumers during a payment processing. The role AP certifies re-encrypted data after verifying the validity of the content from consumers, but with no private information of the consumers required. Each consumer can get a required anonymity level through this new method, depending on the available time, computation and cost. Consumers can also use different banks (cross-payment) and anonymity provider agents (multiple APs) without double-spending problems. Role-based access control is widely used in system management and products since its advantages such as reducing administration cost and complexity. However, conflicting problems may arise between roles when RBAC is applied for system management. For example, mutually exclusive roles may be granted to a user with RBAC and the user may have or derive a high level of authority. To solve these problems, we analyze the duty separation constraints of the roles and role hierarchies in the scheme, then discuss how to grant a role to a user.

Dissertation A research of information hiding and attachment on digital cash and electronic votes

This dissertation presents a research of one-way hash functions on digital cash and electronic votes. All schemes presented in this dissertation were already published in famous journals or conferences. In this dissertation, methods are proposed to hide information in plaintext message or attach specific information to electronic cash and electronic vote. Not only the proposed schemes preserve the anonymity of payers or voters, but also they can be easily implemented on the electronic cash or electronic voting schemes in the literature without affecting their infrastructures. Most important of all, the extra overhead of most of the proposed methods is just several operations of hashing.

A fair E-cash scheme based on elliptic curve cryptography

A new fair off-line electronic cash scheme on elliptic curve cryptography was presented. The new scheme is more efficient than those by extending fair off-line electronic cash scheme from finite field into elliptic curve cryptography and introducing a new elliptic curve discrete logarithm assumption. The expiry date and denomination are embedded into the blindly signed coin by integrating partially blind signature with restrictive blind signature. A bank need not use different public keys for different coin values, shops and users need not carry a list of bank's public keys to verify in their electronic wallet. At the same time, the bank just needs to keep undue electronic coins for double spending check in his database, thus bank's database can be dramatically reduced.

A flexible date-attachment scheme on e-cash

The electronic cash payment system is an important technique that has been utilized for electronic commerce. In this paper, we propose a flexible date attaching method to Chaum’s electronic cash scheme, which can also be applied to many other electronic cash schemes. The date attaching method provides an unforgeable and variable scheme to deal with the effective date of e-cash that will allow for many applications. The customer can modify the date slip but it does not become effective until the merchant passes it on to the bank. Also, the usage of this proposed scheme is very flexible, unlike most e-cash schemes that embed an expiration date when e-cash is withdrawn. This scheme still possesses the untraceability property and the computation complexity for customers and merchants is simple when compared to bank operations.

A faster single-term divisible electronic cash: ZCash

This paper presented a new unlinkable, single-term divisible electronic cash scheme, whose name is ZCash. This scheme overcomes the problems of previous schemes through its greater efficiency and the unlinkability of every cash it generates. Compared with Okamoto’s scheme [Advances in Cryptology—Crypto ’95, Springer, New York, 1995: 438–451] and Chan’s scheme [Advances in Cryptology—Eurocrypt ’98, Springer, New York, 1998: 561–575] (the two best known E-cash schemes), ZCash achieve higher efficiency by not using range-bounded commitment schemes. In addition, to prove the correctness of the blind candidate, we use some simple zero-knowledge protocols instead of the Account Opening protocol and Electronic License. By using the indirect disclosure proof in the payment protocol, ZCash realizes revocable anonymity, which allows a trustee to trace the owner of the E-cash according to its payment transcript. ZCash is the first E-cash scheme which realizes both divisibility and revocable anonymity.

Home care allowances: Good for many but not for all

The author discusses the critical questions that have arisen around the issue of paying cash rather than providing care in kind. These questions include the way recipients use the money, the assessment, the quality of care, the levels of payment and the satisfaction of workers paid with an allowance. She explains how these questions have been handled in five European countries: Austria, France, Germany, the Netherlands and the UK. Although the questions are similar, there is quite a variety in the solutions. Generally speaking, recipients of care allowances are positive about them, because the cash schemes enhance their independence. The author makes some cautionary remarks, concluding that care allowances might not be the best solution for very old, dependent and isolated people

On the design of efficient RSA-based off-line electronic cash schemes

Electronic cash is arguably one of the most important applications of modern cryptology. There have been two types of electronic cash schemes namely on-line and off-line. In general off-line schemes are more efficient than on-line ones. The two fundamental issues with any off-line electronic cash scheme have been the detection of double spending and provision of anonymity. These issues make the design of secure off-line electronic cash schemes not an easy task. Cut-and-choose technology was one of the first techniques that was introduced to address the issue of double spending in an off-line scheme. However, this technique is not very efficient. Subsequently, other techniques had been proposed to achieve both double spending and client anonymity without using the cut and choose method. These include the works of Brands based on the discrete logarithm and that of Ferguson based on RSA and polynomial secret sharing scheme. In this paper, we propose an improved version of off-line electronic cash scheme based on the Ferguson's protocol. This scheme improves the efficiency by making some of the parameters used in the protocol to be reusable and removes the risk of framing by the bank by hiding the client's identity.

The true cost of e‐purse – a Mondex perspective

Argues that the predicted explosion in electronic commerce will be facilitated by low value transactions. Highlights the need for transaction costs to be equally low for this to take place. Two distinct types of electronic cash schemes are evaluated; cleared electronic cash payments schemes such as Proton, GeldKarte, VisaCash and CEPS and non‐cleared payment schemes such as Mondex. Looks at the similarities and differences of the two approaches and the economies of scale that can be achieved by processing high volumes of transactions. Argues that the cost of running cleared payment schemes increases in proportion to the number of purchases being made whereas for non‐cleared schemes such as Mondex they are likely to remain fairly static.

A new higher order effective P–C methods for stiff systems

In this paper a special class of k-step methods of order k+1 with two free parameters up to order 9 are established. The stability analysis of the P–C scheme is investigated. The coefficients of our class and the values of the parameters for getting A 0-stable schemes are tabulated. The relation between the parameters for obtaining L( α)-stable formula is determined. A comparison between the stability region and the error estimation for the fourth-order of our scheme and Cash's scheme is carried on.

Electronic share dealing - the legal issues

This brief critique discusses a recent article by Chen et al. (2011) published in the journal. The authors proposed an electronic cash (e-cash) scheme with trustee-based anonymity revocation from pairing. I found that there are a couple issues that are not properly addressed. (1) The first flaw is that a bank can trace an e-cash payer easily and obtain the payer’s license for illegal usage because the related blind factor that is chosen is fixed, and thus, it is not properly removed from the e-cash in the authors’ scheme. (2) The second flaw is that it is possible for someone to dishonestly cooperate with an honest bank’s customer to defraud the honest bank, and this person’s identity cannot be traced.