Anonymous electronic cash (E-Cash)

Top PDF Anonymous electronic cash (E-Cash):

Divisible Transferable Anonymous Electronic Cash System for General Use

Divisible Transferable Anonymous Electronic Cash System for General Use

Abstract:- In this paper we propose an elegant and unique divisible transferable anonymous electronic cash system with observer. The proposed divisible e-cash solves most of the crucial problems with existing paper cash and untraceable e-cash proposals. Electronic cash provides unconditional anonymity to the user. Research- ers observed, however, that if anonymity in payment system is unconditional, it might be exploited to facilitate crimes like money laundering. This observation spurred research into the idea of making anonymity in payment systems conditional, and, in particular, revocable by a third party or trustee or observer under bank's order. The idea of having an observer is that it can be incorporated in the wallet in such a way that no user module can do a transaction on its own. For any transaction protocol to be executed by the wallet, it needs help (a secret informa- tion) from the observer i.e. the wallet and the observer must confirm mutually when they work together. The advantage of the proposed electronic cash system is that it is able to construct an observer capable of co- operating with divisible and transferable e-cash. Due to the presence of observer, the proposed e-cash has prior resistance of double spending. In each transfer of divisible e-cash, coin authentication and denomination revela- tion is checked to verify the validity of divisible e-cash. In any stage of coin transfer, the anonymity is guaran- teed with protection of double spending.
Show more

12 Read more

An electronic cash scheme and its management

An electronic cash scheme and its management

The system is off-line if the shop does not communicate with the bank during payment. It is untraceable} if there is no p.p.t. TM (probabilistic polynomial-time Turing Machine) that can identify a coin's origin even if one has all the information of withdrawal, payment and deposit transactions. It is anonymous if the bank, in collaboration with the shop, cannot trace the coin to the consumer. However, in the absence of tamper-proof hardware, electronic coins can be copied and spent multiple times by the consumer. This has been traditionally referred to as double-spending. In on-line e-cash, double-spending is prevented by having the bank check if the coin has been deposited before. In off- line e-cash, however, this solution is not possible; instead, as proposed by Chaum, Fiat and Naor [9], the system guarantees that if a coin is double-spent the consumer's identity is revealed with overwhelming probability.
Show more

29 Read more

Scalable  Divisible  E-cash

Scalable Divisible E-cash

Compared to regular cash, electronic payment systems offer greater convenience for end-users, but usually at the cost of a loss in terms of privacy. Introduced in 1982 by Chaum [11], electronic cash (E-cash) is one solution to reconcile the benefits of both solutions. As with regular cash, users of such systems can withdraw coins from a bank and then spend them to different merchants, while remaining anonymous, with unlinkable transactions. There is however one major difference: if a banknote or a coin can hardly be duplicated, this is on the contrary very easy to copy the series of bits constituting an electronic coin, as for any electronic data. It is therefore necessary, when designing an E-cash system, to provide a way of detecting double-spendings (i.e. two spendings using the same coin) and then to allow identification of the underlying defrauder. The challenge is to ensure such features without weakening the anonymity, or the efficiency, of the resulting scheme.
Show more

19 Read more

ELLIPTIC  CURVE BASED UNTRACEABLE OFF-LINE ELECTRONIC CASH SYSTEM

ELLIPTIC CURVE BASED UNTRACEABLE OFF-LINE ELECTRONIC CASH SYSTEM

Gang [12] proposed an anonymous off-line payment scheme involving multiple authorities, in which more than one issuer have the control over the e-coins and the issuers can be selected from the current available issuers list by the customer. Liu et al [13] developed an off line e-cash system which provides recoverability and untraceability. Y. Baseri et al [1] designed an untraceable electronic cash scheme in which the expiration date and the identity of the customer onto the coin are injected and the identity in the case of double spending is detected. ECC based online electronic cash system satisfying the basic requirements, namely customer anonymity, coin tracing, owner tracing, and double spending is developed by Porkodi et al [15]. Cryptography Varadharajan et.al [16] incorporated fairness into the RSA-based e-cash by setting up a set of servers that preserve a threshold cryptosystem such that the servers stay on-line when some error happens and the servers are assumed to preserve user anonymity. Ziba Eslami [17] proposed an untraceable off-line electronic cash scheme with strong fraud control capabilities providing anonymity and dual customer detection.
Show more

10 Read more

A Divisible Transferable E Cash in Wireless Distributed Environment

A Divisible Transferable E Cash in Wireless Distributed Environment

spending occurs. Song and Korba [3] described how to construct an electronic cash scheme which has both features of “untraceability” and “non-repudiation”. This means it can be ensured that a legal user would never be traced; however, once a dispute happens, a user cannot deny that he had spent the electronic cash. Many variants of e-cash scheme have been proposed for different applications. Okamoto [4] proposed a “divisible” electronic cash scheme, which expresses the amount of money by a tree structure to divide the electronic cash into a minimum unit. In the divisible electronic cash scheme, any remainder money can be continually used [5]. Kim et al. proposed a “fair tracing” protocol to protect customers from suffering illegal tracing by a bank or other parties [6]. Camenish et al. proposed a scheme in which once a user spends one of coins in his wallet twice, all coins in his wallet can be traced [7]. Hou and Tan eliminated the withdrawal phase of the electronic cash system. Fair traceability was also provided in their scheme in case of crimes taking place [8]. Chen et al. proposed a scheme that uses a proxy to reduce the burden of the merchant [9]. Chan et al. bounded each procedure in their divisible cash scheme by tens of exponentiations [10]. Camenish et al. proposed a scheme with lower complexity of wallet size [7]. Previously we proposed an internet based anonymous electronic cash system [11, 12]. Wireless operations permit services, such as long range communications, that are impossible or impractical to implement with the use of wires. Mobile communication and computing devices, like laptops and PDAs with WLAN interface cards or cell phones with PDA functionality have become very popular over the last years and we used these devices to run distributed applications using MIWCO. We implemented wireless e-cash so that we can easily transfer divisible transferable anonymous e-cash [15-20] using handheld devices.
Show more

11 Read more

Cash–cash flow sensitivity of pakistani manufacturing firms

Cash–cash flow sensitivity of pakistani manufacturing firms

Kim et al. (1998) investigated the best cash holding level for a firm as well as provide the optimal investment opportunity and it doesn’t spotlight the cash holding for the precautionary objective. For future liquidity requirements manger required to take a decision about the best level of cash holding and decision about the optimal short term investment. They also said that firms get less marginal return on their short term investment for those firms which are financially unconstrained and have additional cash findings. On the other hand financially constrained firms demonstrate nil cash holding and financially unconstrained firms keeps the positive cash holding. Further, firms have to take the objective that because of additional cash funding they have to show the positive cash holding and behind this it shouldn’t be precautionary motives. As reported to Farrari et al. (1998), financially constraints firm should be have high cash flow sensitivity. Which also express the division between internal and external cost and some firms present the higher cash flow sensitivity reason is they have high growth rates, low dividend payout ratio and firms have a small size. According to Kavas and Autore, (2005) findings demonstrate that some firms have an equity issue and they try to go to external financial markets because they have a low information asymmetry. Firm can be escalate their value when firm focus on internal capital market. Besides, the information asymmetry should be low for those firms which have high values.
Show more

6 Read more

Keyword cash funding cash advance funding cash college funding magnum cash funding cash flow funding hard money funding hard money funding network

Keyword cash funding cash advance funding cash college funding magnum cash funding cash flow funding hard money funding hard money funding network

cash register sales cash now tec cash register sharp cash register fast cash no faxing cash register supplies cash register manuals quick cash advance fast cash loan reno no fax cash loan antique cash register fast cash personal loan portable cash register cash registers for sale lil wayne cash money cash register paper casio cash register cash advance software cash flow generator cash money millionares cash advance detroit cash register scanner fast cash loan wisconsin cash til payday
Show more

12 Read more

A Simple Off-line E-Cash System with Observers

A Simple Off-line E-Cash System with Observers

Another practical and secure divisible e-cash system proven secure in random oracle and standard models where the bandwidth of each protocol is constant was presented in [15]. The system [15] also provided with- drawing and spending of an arbitrary value of coins. In [9], Chen et al. proposed an efficient transferable conditional e-payment system based on restrictive partially blind signature scheme. Since the system [9] did not employ cut-and-choose techniques or compli- cated knowledge proof protocols it was less complex in the sense of computation and communication. Pointcheval et al. [17] proposed a first divisible e-cash system without a tree structure that allowed to achieve constant-time complexity with a fairly easy management of coins.
Show more

11 Read more

Cash-flow sensitivities and the allocation of internal cash flow

Cash-flow sensitivities and the allocation of internal cash flow

According to Compustat data manuals, it is important to consider the format code when defining variables using flow-of-funds data. Effective for fiscal years ending on July 15, 1988, Statement of Financial Accounting Standards (SFAS) #95 requires U.S. companies to report the Statement of Cash Flows (format code = 7). Prior to the adoption of SFAS #95, companies may have reported one of the following statements: Working Capital Statement (format code = 1), Cash Statement by Source and Use of Funds (format code = 2), or Cash Statement by Activity (format code = 3). Thus, the variable definitions vary depending on which format code a firm follows in reporting flow-of-funds data. In particular, for investment we include capital expenditure, acquisitions paid by cash, and other investment that result in cash outflows. For issuance and repurchase activities, we consider those that are associated with actual cash inflows or outflows. Following Fama and French (2005), the issuance activities generating no cash flow to the firm, such as granting shares to employees or financing acquisitions with stock, are excluded from our analysis. Table 1 details the construction of all variables in Equation (1) based on different format codes of flow-of-funds data.
Show more

53 Read more

Cash Flow Sensitivity of Cash: A Cross Country Analysis

Cash Flow Sensitivity of Cash: A Cross Country Analysis

This paper makes an important contribution to the contemporary literature by examining the differential cash saving tendency for firms facing different financial constraint status to see the effect of capital market imperfection on international corporate policies. Due to the prolonged debate started with Fazzari et al. (1988) and Kaplan and Zingales (1997) on the ability of investment cash flow sensitivity to capture financial constraints, we have taken up the proposition of Almeida et al. (2004) and rely on cash flow sensitivity of cash to capture the same but in a cross country setting for the first time. Our estimated results from all our model specifications consistently indicate a substantially greater and significantly positive cash saving tendency out of internally generated cash flow for firm years belonging to the most FC categories which are most likely to face more severe asymmetric information related problems. However, the unconstrained firms do not follow any such systematic behavior. Such relationship based on our whole sample remain evident for each of the seven countries as well when analyzed separately which conforms the fact that irrespective of the countries, there are systematic differences between constrained and unconstrained firms in terms of the way they devise their cash hoarding policies. The results suggest important policy implications for FC European firms which should be taken into consideration while managing their working capital and hoard a stock of internal funds to be used as a less costly alternative to external financing for availing profitable investment opportunities. This can potentially get them out of constraint financial status and allow them to enjoy the benefit of a potential positive income shock through their real activities. Our results can guide future researchers to adopt similar investigations on the developing markets and may also influence the managerial decision regarding cash accumulation policy.
Show more

11 Read more

Practical  Compact  E-Cash  with  Arbitrary  Wallet  Size

Practical Compact E-Cash with Arbitrary Wallet Size

Electronic cash (e-cash) was introduced by Chaum [19] in 1982. Basically, an (offline) e-cash scheme consists of three parties (the bank B, user U and merchant M) and three protocols (WithdrawalProtocol, SpendProtocol and DepositProtocol). A user withdraws coins from the bank and applies the coins to pay a merchant (without involving the bank during spending). Then the merchant deposits the coins to the bank. In a compact e-cash scheme a user can withdraw a wallet W containing K coins and can spend each coin unlinkably.

19 Read more

IV CASH FLOWS AND CASH FLOW STRUCTURES

IV CASH FLOWS AND CASH FLOW STRUCTURES

Most securitizations or series are issued with multiple investor classes, such as the Class A certificates (typically triple-A rated), the Class B certificates (typically single-A rated), and Class C certificates (typically triple-B rated). Many series have more classes, including one or more un- rated class held by the selling institution. The pooling and servicing agreement will dictate the required finance charge cash flow allocation for each class within each series, often referred to as the cash flow waterfall. In most cases, the pooling and servicing agreement will allow or require cash flow sharing among the various series in a master trust. In this situation, any excess finance charge cash flows in one series are available to cover any finance charge cash flow shortfalls in another series on a subordinated basis. Exhibit E (above) and Exhibit F (below) are illustrations of relatively simplistic structures. Structures used today by the major issuers have evolved into much more complex structures, but the concept of the cash flow waterfall remains. Nevertheless, it is often challenging to decipher. Prospectuses, prospectus supplements, and pooling and servicing agreements typically use flowcharts to illustrate the structure of the master trust and priority of cash flows.
Show more

11 Read more

Octopus: An E-Cash Payment System Success Story

Octopus: An E-Cash Payment System Success Story

Using smart card technology to replace cash was not new in Hong Kong. Major credit card operators and financial institutions, including MasterCard (Mondex) and VISA (Visa Cash), had been trying to capitalize on such business opportunities since the late 1980s [3]. The economies of scale in card production and application that require a user base of at least one million before a smart card system becomes viable [1] would seem to favor VISA and MasterCard, which enjoyed huge penetration before their e-card systems launched. By late 2000, about 5.8 million VISA cards and 3.3 million MasterCards were in circulation in Hong Kong, while Octopus had no existing client base when initiated. But after several years of trials and development, Mondex and Visa Cash have attained only limited market share compared to the Octopus card. Its extraordinary success is not due to the Octopus card being more technologically secure—in fact, it has fewer security measures than the Mondex and Visa Cash cards—but rather due to the four factors outlined here:
Show more

5 Read more

Fair  Multiple-bank  E-cash  in  the  Standard  Model

Fair Multiple-bank E-cash in the Standard Model

Abstract. Multiple-bank e-cash (electronic cash) model allows users and merchants to open their accounts at different banks which are monitored by the Center Bank. Some multiple-bank e-cash systems were proposed in recent years. However, prior implementations of multiple-bank e-cash all require the random oracle model idealization in their security analysis. We know some schemes are secure in the random oracle model, but are trivially insecure under any instantiation of the oracle. In this paper, based on the automorphic blind signature, the Groth-Sahai proof system and a new group blind signature, we construct a fair multiple-bank e-cash scheme. The new scheme is proved secure in the standard model and provides the following functionalities, such as owner tracing, coin tracing, identification of the double spender and signer tracing. In order to sign two messages at once, we extend Ghadafi’s group blind signature to a new group blind signature. The new signature scheme may be of independent interest.
Show more

30 Read more

Cash Access Account. A Total Cash Management Program

Cash Access Account. A Total Cash Management Program

Move money into the account through direct deposit of your monthly paycheck, pension benefit, Social Security check or another source of income. Or, deposit cash into your account from other sources, such as investment proceeds or dividend income so it can be put to work in your SEI investment account. A securities-backed line of credit makes it easy to borrow against your investments – without disturbing your portfolio.

7 Read more

Accrual accounting, cash accounting and the estimation of future cash flows

Accrual accounting, cash accounting and the estimation of future cash flows

aggregate earnings model and the cash flow model. In addition, disaggregating earnings into cash flows from operations and the accruals components further increases the ability to predict future cash flows compared to disaggregating earnings into cash flows from operations and aggregate accruals. This result is also confirmed by Voung‟s test. The accrual components, with the exception of depreciation and amortisation, are significant predictors of future cash flows with the predicted sign. Whilst, the depreciation and amortisation variable is significant in predicting two and three-year- ahead cash flows. These results are consistent with Al-Attar and Hussain (2004). The result of out-of-sample accuracy tests demonstrate that the cash flows model marginally outperforms the aggregate earnings model in estimating future cash flows for all prediction horizons and disaggregating earnings into cash flows from operations and aggregate accruals improves accuracy of estimating future cash flows; this finding is consistent with the study by Brochet et al (2009) and provides evidence regarding the standard setter‟s point of view that earnings components are important predictors of future cash flows and confirm that accrual accounting is superior to cash accounting. Although the in-sample estimations suggest further improvement when the total accrual is disaggregated into its accrual components but the out-of-sample tests do not provide evidence of a significant improvement in the second stage of disaggregation.
Show more

256 Read more

A Fair Electronic Cash System with Identity Based Group Signature Scheme

A Fair Electronic Cash System with Identity Based Group Signature Scheme

The rest of this paper is as follows: in the next section, we introduce some preliminaries work. Our identity based group signature is presented in Section 3. In Section 4, we propose a new electronic cash system. We explain security analysis of our scheme in Section 5. Final section concludes.

7 Read more

Use of Electronic Payment Instruments and Effect on Cash Management: A Micro Analysis

Use of Electronic Payment Instruments and Effect on Cash Management: A Micro Analysis

The emergence of innovative electronic payment modes in the financial sector has changed the payment dynamics of transactions across countries. The two important modes of card payments offered by the commercial banks are the debit and credit cards in India. This study is an attempt to examine at the micro level the Baumol Tobin model of demand for money in light of the adoption of electronic payment instruments via debit and credit cards among the select households of Coimbatore City for 2017. The estimated results revealed that from across the range of transactions, more than 50 per cent of the respondents chose the mode of cash payment for values lesser than ` 10,000. This indicated that cash was preferred more in the case of low-value transactions. Garrett’s Ranking technique was used to find the impact of usage of debit and credit cards on the financial parameters of the respondents. The results showed that among the respondents usage of debit and credit cards had the highest impact on the “level of indebtedness”, which indicated that the usage of cards for retail purchases substituted cash significantly. JEL: E42 Monetary Systems; Standards; Regimes; Government and the Monetary System; Payment Systems Keywords: Debit cards, credit cards, demand for money, electronic payments, financial innovations, the Indian banking sector
Show more

8 Read more

Cash flows Part II: Analysing the cash flow statement

Cash flows Part II: Analysing the cash flow statement

This may seem counter-intuitive, but it is a good sign to have negative cash flows in this section. This is because it represents investments in the future. However, the key thing is having the cash to pay for these items – and Timbercorp certainly isn’t generating that cash from its day-to-day operations. So the question we must ask is:

5 Read more

Estimation of corporation’s cash flows based on cash flow statement

Estimation of corporation’s cash flows based on cash flow statement

Summary: In the paper the problem points to evaluate cash flows corporation based on the statement of cash flows. The essence of bank’s «cash flow», it’s classification and impacts identified and methodical basis of the statement of cash flows. Investigated the procedure and submission Cash flow statement of the bank. Practical aspects of improving methods of preparation and analysis Cash flow statement of the bank. Proved that the cash management of joint stock companies is necessary for the effective functioning of the economic mechanism, capacity building for the development of undertakings, efficient use of capital, support competitiveness and investment attractiveness of undertakings and to ensure financial stability and economic growth.
Show more

12 Read more

Show all 10000 documents...