• The Journal of Society for e-Business Studies
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• v.4 no.1
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• pp.103-115
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• 1999

The electronic cash, an electronic equivalent of the real paper money, has been recently proposed as one of the various payment methods for electronic commerce. In this paper, we design an electronic cash payment system based on a new electronic cash payment protocol that can effectively provide full anonymity and avoid double-spending. The protocol is suitable for use as the electronic cash control or electronic cash database. The protocol support also security and electronic cash property.

• Korea Journal of Hospital Management
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• v.10 no.1
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• pp.48-70
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• 2005

The purpose of this study was to make an analysis of the impact of the DRG payment system on medical care pattern and cost of cataract surgery in a general hospital. The subjects were 173 patients whose DRG severity grade was zero, selected from among the hospitalized who underwent cataract surgery before and after the joining to the demonstrational operation of the third year DRG payment system. Their medical records and the details of their medical bills were examined to find out the length of hospital stay, medical care pattern provided to them, the cost of medical care, and the quality of medical care. The length of stay and the amount of medical care supplied during being in hospital dropped significantly for both single-eye and double-eyes cataract surgery groups. The amount of antibiotic use went down during the hospitalization and upon discharge from the hospital, but decreased after discharge. The total medical bills and the rate of basic examination implementation increased in the OPD before hospitalization but after discharge dropped. For double-eyes cataract patients, the rate of double-eyes cataract surgery went down. The total medical bills of DRG payment system converted into the fee-for-service system was greater by 113.3% for the single-eye cataract surgery group and by 102.9% for the doble-eyes cataract surgery group, compared to that by the fee-for-service. The contribution shared by the insurance corporation increased for both single-eye and double-eyes cataract surgery groups, but the copayment by the insured went down. Regarding the treatment outcome, no difference was found in complication rate, resurgery rate and mortality rate before and after the joining to the DRG payment system was implemented. The use of special lens lessened significantly. The amount of medical care supplied during hospitalization decreased but the complication rate didn't increase. But the increased use of low-price artificial cataract and the avoidance of double-eyes cataract surgery was observed. The phenomenon decreased number of OPD visit and the decreased total medical bills of OPD care after discharge in this hospital required further evaluation.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.1
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• pp.97-101
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• 1999

The most important technical problem in EC is about secure electronic payment systems. Electronic payment systems come three different types distinguished by the payment method: electronic cash, electronic check, and creditcard. In these types, electronic cash payment system is popular and practical as in real commerce. But electronic cash can be copied easily, then it is infeasible to prevent user from double-spending a coin. In this paper, we overview several requirements for secure electronic payment system and present other proposed additions to the results. At last we present a model system which considers requirements above examined.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2628-2645
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• 2017

This paper proposes a new offline electronic payment (e-payment) system that satisfies the major security requirements of e-payment, i.e. anonymity, unlinkability, unforgeability, double spending control, conditional traceability, and fraud prevention. The central idea is the use of Hwang et al.'s RSA-based untraceable blind signature (BS), which disables the link between the e-coin and its owner and ensures the anonymity of both the customer and the merchant. It attaches an expiration, a deposit and the transaction dates to each e-coin in order to manage the database of the bank effectively, to correctly calculate the interest on the e-coin and to aid arbitration if a dishonest customer attempts to double-spend the coin. It also ensures the anonymity of the customer as long as the coin is spent legitimately. Only when a fraudulent e-coin transaction is detected can the bank, with the help of the central authority (a trusted entity), determine the identity of the dishonest customer. The system is referred to as offline since the bank does not need to be concurrently involved in transactions between a customer and a merchant. Finally, analyses of the performance of the prototype and the primary security requirements of the proposed system are also presented.

• Korean Journal of Organic Agriculture
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• v.28 no.3
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• pp.273-288
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• 2020

The purpose of this study is to estimate farmers' willingness to accept (WTA) of direct payment for increasing public benefit using the contingent valuation method. The double-bounded dichotomous choice and the open-ended question were used to measure WTAs for basic form and optional form, respectively. The results show that WTA for basic form was inversely proportional to the acreage. WTAs were KRW 1,694,001 with 2 ha or less, KRW 1,617,789 with over 2 ha~6 ha, and KRW 1,562,977 with over 6 ha. The results also indicate that WTAs for optional form are similar to payments of agricultural environmental conservation program except physical (chemical) control of pests and weed. The results of this study can provide useful information for the establishment of direct payment for increasing public benefit.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.113-119
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• 2003

In WISA 2002, Ham et al. proposed a one-way mobile payment system. They claimed that the electronic cash of the system satisfies unforgeability and double spending prevention. In this paper, we point out that their system is not secure as they claimed by showing that the forgery of payment scripts is possible.

• The Journal of Fisheries Business Administration
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• v.49 no.3
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• pp.85-99
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• 2018

This study is to compare and evaluate the estimating method of WTP(willingness to pay) for the valuation of oceans and fisheries resources with non-market goods characteristics using contingent valuation method. In general, when estimating parameters of the WTP function, we should take into account the assumption of probability distribution, inclusion of covariates, method of inducement of payment, and the treatment of 0 payment intention and resistance responses. This study utilizes survey data that was used to estimate the value of fisheries resource protection zones, with a total of 1,200 samples. The main results of this study are summarized as follows: First, the final willness to pay amount is estimated at a statistical significance of less than 1 percent, and the distribution of the final willness to pay amount is from \6,926 of the double bounded dichotomous model to \10,721 of the spike model. Second, the willness to pay amount based on assumptions about the normal and logistic probability distributions are estimated to be \9,429 and \9,370 respectively, so there was no significant difference. Third, the willness to pay amount of the single bounded dichotomous model and the double bounded dichotomous model are estimated to be \8,951 and \6,926 respectively, making a relatively large difference. Fourth, the willness to pay amount of the model without covariates and the model with covariates are estimated to be \9,429 and \8,951, respectively, so the willness to pay amount is underestimated when the covariates are included. Fifth, the Spike model that considers zero payment intention and resistance response estimates \10,405 as the highest payment in this study. Finally, the CVM analysis guidelines proposed by the Korea Development Institute (KDI) are estimated to be \9,749 and \10,405 respectively, depending on including no covariates and with covariates. Compared to other models, the final willness to pay amount is not estimated underestimated. Therefore this study suggests the use of KDI's guidance under government public policy projects. In view of these results, the estimating model for willness to pay amount model will be selected by considering the sample size, the suitability of the model, the sign of the estimated coefficient, the statistical significance, the ratio of the zero payment intention and the payment rejection. And, for CVMs on government public policy projects, it is desirable to estimate by the method proposed by the KDI.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.10
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• pp.752-760
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• 2009

Emerging peer-to-peer systems benefit from the large amount of resources provided by many peers. However, many peer-to-peer systems or applications suffer from malicious peers and it is not guaranteed that peers are always online. Micropayment systems are accounting and charging mechanism for buying services, so we can apply them to solve these problems. In the past the majority of micropayment system uses a centralized broker but the problem with most existing micropayment system is a heavy load on the broker. For instance, when an owner of the coin is offline, the broker delegates the owner and handles payment messages. It occurs frequently because of characteristic of peer-to-peer system and is another load of the broker. In this paper we introduce DPay, a peer-to-peer micropayment system that uses distributed hash table (DHT) for storing encrypted payment messages and increases scalability and reduces the load of broker by removing downtime protocol. We show the idea of real-time double spending detection in DPay and report the results of several evaluations in order to compare DPay and other payment scheme. In simulation result, the load of broker in DPay is reduced by 30% on average of other previous payment scheme. We expect that DPay can apply various peer-to-peer systems because it provides a real-time double spending detection and stores more secure payment messages.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.408-416
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• 2003

An electronic cash system has to provide the security, to prevent the double spending and to support the divisibility of electronic cash for the easy of use. Divisible electronic cash system allows an electronic cash to be divided into subdivisions. Each subdivision is worth any desired value, but all values must add up to the original cash value. Divisible scheme brings some advantages. It reduces to make the change and also there is no necessity that a customer must withdraw a cash of the desired value whenever transactions occur. In this paper, we present an electronic cash protocol which provides the divisibility based on the double hash chain technique. Electronic cash is constructed in the form of coins. Coins, generated by the double hush chain, have different denominations. The divisibility based on the double hash chain technique. Electronic cash is constructed in the form of coins. Coins, generated by the double hash chain, have different denominations. The divisibility of an electronic cash is satisfied by the payment certificate, which is a pair of bank´s proxy signature received from the bank. When a customer pays the coin of subdivision, the fairness of that coin is certified by a customer´s signing instead of a bank. Although the proposed method does not guarantee user´s anonymity, it generates coins which cannot be forged, and the customer can use an electronic cash conveniently and efficiently with its divisibility.

• The Journal of Information Technology
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• v.4 no.2
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• pp.155-174
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• 2001

Dramatic changes are beginning to occur in payment system according to increase electronic commerce. and so electronic money as a new payment system are increase role in new and innovative systems. There are two type Electronic money as a IC card type and network-type. Advanced card technologies such as IC-card are playing an increasingly important role in new and Innovation system. The merit of IC-card are more capacity, more secure, more reliable, quick and easy to update, secure offline processing, enabling technology etc than magnetic stripe card. And so many countries began using experiment of IC- card and our country began October 13 in Cheju island. Then there are four types using-experiment (K-cash, VISA-cash, A-cash, MONDEX) in Korea. There are some problems such as standards, widely using, high cost, double investment etc. I think that important things in IC-card using is an international- standardizations and issuing corporation.