The Nuts and Bolts of Micropayments: A Survey
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paper_title: A Framework for Micropayment Evaluation

paper_content:

Lacking payment systems become a bottleneck for the vision of the Information Economy. In many cases, the payments of a fraction of a cent, the so-called micropayments, are of particular interest. In this paper we propose a framework to evaluate the payment systems. The framework consists of a well structured parameter vector of the desired attributes. For the evaluation of attribute values, we suggest to use VTS diagrams from object-oriented analysis and design. The framework is applied to DigiCash, SET and First Virtual.
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paper_title: User Perceptions of Sharing, Advertising, and Tracking

paper_content:

Extending earlier work, we conducted an online user study to investigate users’ understanding of online behavioral advertising (OBA) and tracking prevention tools (TPT), and whether users’ willingness to share data with advertising companies varied depending on the type of first party website. We presented results of 368 participant responses across four types of websites an online banking site, an online shopping site, a search engine and a social networking site. In general, we identified that participants had positive responses for OBA and that they demonstrated clear preferences for which classes of information they would like to disclose online. Our results generalize over a variety of website categories containing data with different levels of sensitivity, as opposed to only the medical context as was shown in previous work by Leon et al. In our study, participants’ privacy attitudes significantly dominated their sharing willingness. Interestingly, participants appreciated the idea of user-customized targeted ads and some would be more willing to share data if given prior control mechanisms for tracking protection tools.
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paper_title: The Case against Micropayments

paper_content:

Micropayments are likely to continue disappointing their advocates. They are an interesting technology. However, there are many non-technological reasons why they will take far longer than is generally expected to be widely used, and most probably will play only a minor role in the economy.
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paper_title: MICRO PAYMENT GATEWAYS

paper_content:

The main objective of this thesis is to develop an architecture of the hybrid payment system.
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paper_title: A Framework for Micropayment Evaluation

paper_content:

Lacking payment systems become a bottleneck for the vision of the Information Economy. In many cases, the payments of a fraction of a cent, the so-called micropayments, are of particular interest. In this paper we propose a framework to evaluate the payment systems. The framework consists of a well structured parameter vector of the desired attributes. For the evaluation of attribute values, we suggest to use VTS diagrams from object-oriented analysis and design. The framework is applied to DigiCash, SET and First Virtual.
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paper_title: The case against micropayments

paper_content:

In the coking of spent ammonia and low pH sodium base sulfite wood pulping liquors in the liquid phase under pressure, gel-type coke formation is avoided by rapid heating to the coking temperature. Such rapid heating can be accomplished by the use of a metal bath having high heat transfer capacity, by using high pressure-high temperature steam injection or by means of a fluidized bed combustion system. The heating rate used is one of about 110 DEG to about 150 DEG F. per minute in the temperature interval of about 350 DEG to about 550 DEG F.
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paper_title: Chrg-http: A Tool for Micropayments on the World Wide Web

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Chrg-http is a simple and secure protocol for electronic payments over the Internet, especially in an intranet environment. It is designed to support those micropayments (or more specific, electronic publishing, which have costs ranging from pennies to a few dollars. A widely used secure system Kerberos V5 has been incorporated into the http protocol. The security and authentication of a transactions is provided by Kerberos, without expensive public key cryptographic computations, or on-line processing through a centralized payment processing server, which is the case to most of the existing electronic payment systems on the World Wide Web. Our implementation is based on the billing model (or the subscription model). The simplicity of the model also helps to reduce the charging cost overhead.
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paper_title: NetCents : A Lightweight Protocol for Secure Micropayments

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NetCents is a lightweight, flexible and secure protocol for electronic commerce over the Internet that is designed to support purchases ranging in value from a fraction of a penny and up. NetCents differs from previous protocols in several respects: NetCents uses (vendor-independent) floating scrips as signed containers of electronic currency, passed from vendor to vendor. This allows NetCents to incorporate decentralized verification of electronic currency at a vendor's server with offline payment capture. Customer trust is not required within this protocol and a probabilistic verification scheme is used to effectively limit vendor fraud. An online arbiter is implemented that will ensure proper delivery of purchased goods and that can settle most customer/vendor disputes. NetCents can be extended to support fully anonymous payments. In this paper we describe the NetCents protocol and present experimental results of a prototype implementation.
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paper_title: A Payment Scheme Using Vouchers

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Electronic payment schemes are traditionally based on the physical model of commerce where customers withdraw cash from bank accounts and spend it at merchants' establishments in return for goods and services. This may not be the most ideal model on which to base electronic payment. A new payment scheme using a different paradigm has been developed. Vouchers are prepared by the bank and the merchant. These are distributed to customers who can redeem them for electronic goods with the help of the bank. This new scheme requires fewer online messages to be transmitted than previous payment schemes involving electronic goods such as NetBill and thus also requires less online processing. The voucher scheme also provides some properties desired by payment schemes based on electronic coins.
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paper_title: Agora: a minimal distributed protocol for electronic commerce

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Agora is a Web protocol for electronic commerce, which is intended to support high-volume of transactions each with low incurred cost. Agora has the following novel properties: • Minimal. The incurred cost of Agora transactions is close to free Web browsing where cost is determined by the number of messages. • Distributed. Agora is fully distributed. Merchants can authenticate customers without access to a central authority. Customers with valid accounts can purchase from any merchant without any preparations (such as prior registration at the merchant or at a broker). • On-line arbitration. An on-line arbiter can settle certain customer/merchant disputes. • Fraud control. Agora can limit the degree of fraud to a pre-determined (low) level. ::: ::: Agora is authenticated secure and can not be repudiated. It can use regular (insecure) communication channels.
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paper_title: Pricing via processing or combatting junk mail

paper_content:

We present a computational technique for combatting junk mail in particular and controlling access to a shared resource in general. The main idea is to require a user to compute a moderately hard, but not intractable, function in order to gain access to the resource, thus preventing frivolous use. To this end we suggest several pricing Junctions, based on, respectively, extracting square roots modulo a prime, the Fiat-Shamir signature scheme, and the Ong-Schnorr-Shamir (cracked) signature scheme.
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paper_title: The S/KEY One-Time Password System

paper_content:

This document describes the S/KEY* One-Time Password system as released for public use by Bellcore and as described in reference [3]. A reference implementation and documentation are available by anonymous ftp from ftp.bellcore.com in the directories pub/nmh/...
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paper_title: NetPay: An off-line, decentralized micro-payment system for thin-client applications

paper_content:

Micro-payment systems have become popular in recent times as the desire to support low-value, high-volume transactions of text, music, clip-art, video and other media has increased. We describe NetPay, a micro-payment system characterized by de-centralized, off-line processing, customer anonymity and relatively high performance and security using one-way hashing functions for encryption. We describe the motivation for NetPay and its basic protocol, describe a software architecture and two NetPay prototypes we have developed, and report the results of several evaluations of these prototypes.
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paper_title: MiMi: A Java Implementation of the MicroMint Scheme

paper_content:

In this paper we describe an experimental implementation of the MicroMint micropayment scheme in Java. We apply this scheme to purchasing Web pages. A prerequisite was to accomplish this without having to change the code of either the Web server or the Web client. We discuss the implementation issues and security considerations. Our implementation requires the local protocol handler feature offered by Sun Microsystems’ HotJava 1.0 browser.
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paper_title: A pay word-based micropayment protocol supporting multiple payments

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In this paper, we propose an efficient micropayment protocol by improving PayWord, which is one of the representative micropayment protocols. In the original PayWord system, it was designed for a customer who generates paywords by performing hash chain operation for payments to an only designated vendor. In other words, the customer has to create new paywords in order to establish commercial transactions with different vendors on the Internet. To supplement this drawback, our proposed scheme provides a useful method to do business with multiple vendors for a customer with only one hash chain operation. In our proposed protocol, a broker creates a new series of hash chain values along with a certificate for the certificate request of a customer. This certificate is signed by the broker to give authority enabling the customer to make paywords. Our proposed scheme provides an efficient means for the customer to do business with multiple vendors.
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paper_title: Hashcash - A Denial of Service Counter-Measure

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Hashcash was originally proposed as a mechanism to throttle systematic abuse of un-metered internet resources such as email, and anonymous remailers in May 1997. Five years on, this paper captures in one place the various applications, improvements suggested and related subsequent publications, and describes initial experience from experiments using hashcash. The hashcash CPU cost-function computes a token which can be used as a proof-of-work. Interactive and noninteractive variants of cost-functions can be constructed which can be used in situations where the server can issue a challenge (connection oriented interactive protocol), and where it can not (where the communication is store–and– forward, or packet oriented) respectively.
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paper_title: Electronic Payments of Small Amounts

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This note considers the application of electronic cash to transactions in which many small amounts must be paid to the same payee and in which it is not possible to just pay the total amount afterwards. The most notable example of such a transaction is payment for phone calls. If currently published electronic cash systems are used and a full payment protocol is executed for each of the small amounts, the overall complexity of the system will be prohibitively large (time, storage and communication). This note describes how such payments can be handled in a wide class of payment systems. The solution is very easy to adapt as it only influences the payment and deposit transactions involving such payments. Furthermore, making and verifying each small payment requires very little computation and communication, and the total complexity of both transactions is comparable to that of a payment of a fixed amount.
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paper_title: An Implementation of MicroMint

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This thesis describes a prototype implementation of MicroMint, an Internet micropayment system designed to facilitate very small scale monetary transactions over the World Wide Web. By implementing a proposed system, we can determine its feasibility for real commercial applications, and identify advantages and disadvantages inherit in different systems. This prototype implementation pays special attention to details necessary for end users to adopt the payment system easily. Thesis Supervisor: Ronald L. Rivest Title: Professor
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paper_title: Password authentication with insecure communication

paper_content:

A method of user password authentication is described which is secure even if an intruder can read the system's data, and can tamper with or eavesdrop on the communication between the user and the system. The method assumes a secure one-way encryption function and can be implemented with a microcomputer in the user's terminal.
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paper_title: Transactions Using Bets

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Small cash transactions, electronic or otherwise, can have their overhead costs reduced by Transactions Using Bets (TUB), using probablistic expectation (betting) as a component. Other types of protocols may also benefit from this idea.
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paper_title: An Efficient Micropayment System Based on Probabilistic Polling

paper_content:

Existing software proposals for electronic payments can be divided into “on-line” schemes that require participation of a trusted party (the bank) in every transaction and are secure against overspending, and the “off-line” schemes that do not require a third party and guarantee only that overspending is detected when vendors submit their transaction records to the bank (usually at the end of the day). We propose a new hybrid scheme that combines the advantages of both of the above traditional design strategies. It allows for control of overspending at a cost of only a modest increase in communication compared to the off-line schemes. Our protocol is based on probabilistic polling. During each transaction, with some small probability, the vendor forwards information about this transaction to the bank. This enables the bank to maintain an accurate approximation of a customer's spending. The frequency of polling messages is related to the monetary value of transactions and the amount of overspending the bank is willing to risk.
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paper_title: Electronic lottery tickets as micropayments

paper_content:

We present a new micropayment scheme based on the use of “electronic lottery tickets.” This scheme is exceptionally efficient since the bank handles only winning tickets, instead of handling each micropayment.
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paper_title: A p2p market place based on aggregate signatures

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A peer-to-peer market place is likely to be based on some underlying micro-payment scheme where each user can act both as a customer and as a merchant. Such systems, even when designed for largely distributed domains, may be implemented according to hybrid topologies where trusted third intermediaries (e.g. the broker) are single points of failures. For this reason it is crucial that such central entities scale well w.r.t. the overall number of transactions. In this paper, we focus on PPay as a case study, to show how the broker would greatly benefit in terms of computational cost if aggregate signatures are adopted instead of RSA signatures.
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paper_title: To Share or not to Share: An Analysis of Incentives to Contribute in Collaborative File Sharing Environments

paper_content:

Projects developing infrastructure for the pooling of distributed resources (data, storage, or computation) [1, 2] often assume that resource owners have committed their resources and that the chief task is to integrate and use them efficiently. Such projects frequently ignore the question of whether individual resource owners are willing to share their personal resources for the overall good of the community. However, experiences [3-6] with peer-to-peer (P2P) file sharing systems like Gnutella, Napster, and Kazaa suggest that users are not altruistic. In Gnutella, for example, 70% of all users do not share files, and 50% of all requests are satisfied by the top 1% sharing hosts. Thus, incentive mechanisms that motivate users to contribute resources may be critical to eventual success of such systems. Various approaches to incentives have been proposed, including pricing or micro-currency schemes [7] and so-called “soft incentive” or nonpricing schemes [8]. However, the effectiveness of these different schemes is not well understood. In this paper we take a step towards understanding the performance of incentive schemes by defining and applying an analytic model based on Schelling’s Multi-Person Prisoner’s Dilemma (MPD) [9]. We use both this framework and simulations to study the effectiveness of different schemes for encouraging sharing in distributed file sharing systems. We consider three such schemes: the soft-incentive, reputation-based Peer-Approved and Service-Quality, and the Token-Exchange pricing scheme. After introducing the MPD model (Section 2), we use it to explain the rational behavior of users in a P2P file sharing community without incentives (Section 3). We then analyze user behavior when Peer-Approved is used as the incentive mechanism and find that it is effective in incentivizing rational users to share more files (Section 4). We then shift to the use of simulations so as to look beyond the assumptions of the MPD model. We measure the effectiveness of the reputation-based soft-incentive Peer-Approved scheme and compare it with that of the Token-Exchange pricing scheme (in Section 5). We find that even simple soft-incentive schemes can motivate users of P2P file-sharing systems to increase contributions in a way that benefits all users, including themselves.
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paper_title: P2P-NetPay: An Off-line Micro-payment System for Content Sharing in P2P-Networks

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Micro-payment systems have the potential to provide non-intrusive, high-volume and low-cost pay-asyou- use services for a wide variety of web-based applications. We proposed a new model, P2P-NetPay, a micro-payment protocol characterized by off-line processing, suitable for peer-to-peer network service charging. P2P micro-payment systems must provide a secure, highly efficient, flexible, usable and reliable environment, the key issues in P2P micro-payment systems development. Therefore, in order to assist in the design and implementation of an efficient micro-payment system suitable for P2P networks, we describe a prototype architecture for a new P2P-based micro-payment model based on NetPay micropayment system. We present an object-oriented design and describe a prototype implementation of P2P-NetPay for a file-sharing P2P system. We report on initial evaluation results deploying our P2P-NetPay prototype and outline directions for future research in P2P micro-payment implementations.
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paper_title: Bitcoin and Beyond: A Technical Survey on Decentralized Digital Currencies

paper_content:

Besides attracting a billion dollar economy, Bitcoin revolutionized the field of digital currencies and influenced many adjacent areas. This also induced significant scientific interest. In this survey, we unroll and structure the manyfold results and research directions. We start by introducing the Bitcoin protocol and its building blocks. From there we continue to explore the design space by discussing existing contributions and results. In the process, we deduce the fundamental structures and insights at the core of the Bitcoin protocol and its applications. As we show and discuss, many key ideas are likewise applicable in various other fields, so that their impact reaches far beyond Bitcoin itself.
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paper_title: Scalability evaluation of a peer-to-peer market place based on micro payments

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A fair peer-to-peer market place should protect intellectual properties as well as account peers that act as distributors of the source. FairPeers is a scheme in which some central authorities are necessary, with the drawback that when the number of transactions grows, these entities can represent single points of failure. This paper proposes a generic model to analytically evaluate such a market place and estimate its performance in terms of scalability w.r.t. the total number of printed coins and the overall transactions that can occur in the given peer-to-peer system.
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paper_title: WhoPay: A Scalable and Anonymous Payment System for Peer-to-Peer Environments

paper_content:

An electronic payment system ideally should provide security, anonymity, fairness, transferability and scalability. Existing payment schemes often lack either anonymity or scalability. In this paper we propose WhoPay, a peer-topeer payment system that provides all the above properties. For anonymity, we represent coins with public keys; for scalability, we distribute coin transfer load across all peers, rather than rely on a central entity such as the broker. This basic version of WhoPay is as secure and scalable as existing peer-to-peer payment schemes, while providing a much higher level of user anonymity. We also introduce the idea of real-time double spending detection by making use of distributed hash tables (DHT). Simulation results show that the majority of the system load is handled by the peers under typical peer availability, indicating that WhoPay should scale well.
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paper_title: Off-Line micro-payment system for content sharing in p2p networks

paper_content:

Micro-payment systems have the potential to provide non-intrusive, high-volume and low-cost pay-as-you-use services for a wide variety of web-based applications. We propose an extension, P2P-NetPay, a micro-payment protocol characterized by off-line processing, suitable for peer-to-peer network services sharing. Our approach provides high performance and security using one-way hashing functions for e-coin encryption. In our P2P-NetPay protocol, each peer's transaction does not involve any broker and double spending is detected during the redeeming transaction. We describe the motivation for P2P-NetPay and describe three transactions of the P2P-NetPay protocol in detail to illustrate the approach. We then discuss future research on this protocol.
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paper_title: KARMA: A Secure Economic Framework for Peer-to-Peer Resource Sharing

paper_content:

Peer-to-peer systems are typically designed around the assumption that all peers will willingly contribute resources to a global pool. They thus suffer from freeloaders, that is, participants who consume many more resources than they contribute. In this paper, we propose a general economic framework for avoiding freeloaders in peer-to-peer systems. Our system works by keeping track of the resource consumption and resource contribution of each participant. The overall standing of each participant in the system is represented by a single scalar value, called their karma. A set of nodes, called a bankset, keeps track of each node’s karma, increasing it as resources are contributed, and decreasing it as they are consumed. Our framework is resistant to malicious attempts by the resource provider, consumer, and a fraction of the members of the bank set. We illustrate the application of this framework to a peer-to-peer filesharing
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paper_title: Constructing Fair-Exchange P2P File Market

paper_content:

P2P is a promising technology to construct the underlying supporting layer of a Grid. It is known that contribution from all the peers is vital for the sustainability of a P2P community, but peers are often selfish and unwilling to contribute. In this paper we describe how to construct a fair file-exchanging P2P community. We name this community a P2P file market. Our scheme forces peers to contribute by a micropayment-based incentive mechanism.
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paper_title: Regarding timeliness in the context of fair exchange

paper_content:

In this paper we discuss the often overlooked timeliness property of fair exchange protocols. We gather different available definitions of this property, and propose a new and stronger interpretation for timeliness in the context of security protocols. We discuss common timeliness-related pitfalls in fair exchange protocol design, and show a particular timeliness attack effective in several optimistic protocols proposed in the literature. Finally, we provide guidelines that may help to avoid common mistakes in protocol design, and propose our own protocol that ensures both fairness and timeliness.
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paper_title: PPay: micropayments for peer-to-peer systems

paper_content:

Emerging economic P2P applications share the common need for an efficient, secure payment mechanism. In this paper, we present PPay, a micropayment system that exploits unique characteristics of P2P systems to maximize efficiency while maintaining security properties. We show how the basic PPay protocol far outperforms existing micropayment schemes, while guaranteeing that all coin fraud is detectable, traceable and unprofitable. We also present and analyze several extensions to PPay that further improve efficiency.
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paper_title: A fistful of bitcoins: characterizing payments among men with no names

paper_content:

Bitcoin is a purely online virtual currency, unbacked by either physical commodities or sovereign obligation; instead, it relies on a combination of cryptographic protection and a peer-to-peer protocol for witnessing settlements. Consequently, Bitcoin has the unintuitive property that while the ownership of money is implicitly anonymous, its flow is globally visible. In this paper we explore this unique characteristic further, using heuristic clustering to group Bitcoin wallets based on evidence of shared authority, and then using re-identification attacks (i.e., empirical purchasing of goods and services) to classify the operators of those clusters. From this analysis, we characterize longitudinal changes in the Bitcoin market, the stresses these changes are placing on the system, and the challenges for those seeking to use Bitcoin for criminal or fraudulent purposes at scale.
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paper_title: Micropayments for Decentralized Currencies

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Electronic financial transactions in the US, even those enabled by Bitcoin, have relatively high transaction costs. As a result, it becomes infeasible to make micropayments, i.e. payments that are pennies or fractions of a penny. In order to circumvent the cost of recording all transactions, Wheeler (1996) and Rivest (1997) suggested the notion of a probabilistic payment, that is, one implements payments that have expected value on the order of micro pennies by running an appropriately biased lottery for a larger payment. While there have been quite a few proposed solutions to such lottery-based micropayment schemes, all these solutions rely on a trusted third party to coordinate the transactions; furthermore, to implement these systems in today's economy would require a a global change to how either banks or electronic payment companies (e.g., Visa and Mastercard) handle transactions. We put forth a new lottery-based micropayment scheme for any ledger-based transaction system, that can be used today without any change to the current infrastructure. We implement our scheme in a sample web application and show how a single server can handle thousands of micropayment requests per second. We provide an analysis for how the scheme can work at Internet scale.
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paper_title: Decentralized Anonymous Micropayments

paper_content:

Micropayments (payments worth a few pennies) have numerous potential applications. A challenge in achieving them is that payment networks charge fees that are high compared to “micro” sums of money.
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paper_title: Towards Bitcoin Payment Networks

paper_content:

Bitcoin as deployed today does not scale. Scalability research has focused on two directions: 1 redesigning the Blockchain protocol, and 2 facilitating 'off-chain transactions' and only consulting the Blockchain if an adjudicator is required. In this paper we focus on the latter and provide an overview of Bitcoin payment networks. These consist of two components: payment channels to facilitate off-chain transactions between two parties, and the capability to fairly exchange bitcoins across multiple channels. We compare Duplex Micropayment Channels and Lightning Channels, before discussing Hashed Time-Locked Contracts which enable Bitcoin-based payment networks. Finally, we highlight challenges for route discovery in these networks.
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paper_title: 1 Beware the Middleman: Empirical Analysis of Bitcoin-Exchange Risk

paper_content:

Bitcoin has enjoyed wider adoption than any previous crypto- currency; yet its success has also attracted the attention of fraudsters who have taken advantage of operational insecurity and transaction irreversibility. We study the risk investors face from Bitcoin exchanges, which convert between Bitcoins and hard currency. We examine the track record of 40 Bitcoin exchanges established over the past three years, and find that 18 have since closed, with customer account balances often wiped out. Fraudsters are sometimes to blame, but not always. Using a proportional hazards model, we find that an exchange’s transaction volume indicates whether or not it is likely to close. Less popular exchanges are more likely to be shut than popular ones. We also present a logistic regression showing that popular exchanges are more likely to suffer a security breach.
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paper_title: 1 Beware the Middleman: Empirical Analysis of Bitcoin-Exchange Risk

paper_content:

Bitcoin has enjoyed wider adoption than any previous crypto- currency; yet its success has also attracted the attention of fraudsters who have taken advantage of operational insecurity and transaction irreversibility. We study the risk investors face from Bitcoin exchanges, which convert between Bitcoins and hard currency. We examine the track record of 40 Bitcoin exchanges established over the past three years, and find that 18 have since closed, with customer account balances often wiped out. Fraudsters are sometimes to blame, but not always. Using a proportional hazards model, we find that an exchange’s transaction volume indicates whether or not it is likely to close. Less popular exchanges are more likely to be shut than popular ones. We also present a logistic regression showing that popular exchanges are more likely to suffer a security breach.
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paper_title: Bitcoin: Perils of an Unregulated Global P2P Currency

paper_content:

Bitcoin has, since 2009, become an increasingly popular online currency, in large part because it resists regulation and provides anonymity. We discuss how Bitcoin has become both a highly useful tool for criminals and a lucrative target for crime, and argue that this arises from the same essential ideological and design choices that have driven Bitcoin's success to date. In this paper, we survey the landscape of Bitcoin-related crime, such as dark markets and bitcoin theft, and speculate about possible future possibilities, including tax evasion and money laundering.
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paper_title: 1 Beware the Middleman: Empirical Analysis of Bitcoin-Exchange Risk

paper_content:

Bitcoin has enjoyed wider adoption than any previous crypto- currency; yet its success has also attracted the attention of fraudsters who have taken advantage of operational insecurity and transaction irreversibility. We study the risk investors face from Bitcoin exchanges, which convert between Bitcoins and hard currency. We examine the track record of 40 Bitcoin exchanges established over the past three years, and find that 18 have since closed, with customer account balances often wiped out. Fraudsters are sometimes to blame, but not always. Using a proportional hazards model, we find that an exchange’s transaction volume indicates whether or not it is likely to close. Less popular exchanges are more likely to be shut than popular ones. We also present a logistic regression showing that popular exchanges are more likely to suffer a security breach.
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paper_title: For sale : your data: by : you

paper_content:

Monetizing personal information is a key economic driver of online industry. End-users are becoming more concerned about their privacy, as evidenced by increased media attention. This paper proposes a mechanism called 'transactional' privacy that can be applied to personal information of users. Users decide what personal information about themselves is released and put on sale while receiving compensation for it. Aggregators purchase access to exploit this information when serving ads to a user. Truthfulness and efficiency, attained through an unlimited supply auction, ensure that the interests of all parties in this transaction are aligned. We demonstrate the effectiveness of transactional privacy for web-browsing using a large mobile trace from a major European capital. We integrate transactional privacy in a privacy-preserving system that curbs leakage of information. These mechanisms combine to form a market of personal information that can be managed by a trusted third party.
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paper_title: The Case against Micropayments

paper_content:

Micropayments are likely to continue disappointing their advocates. They are an interesting technology. However, there are many non-technological reasons why they will take far longer than is generally expected to be widely used, and most probably will play only a minor role in the economy.
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paper_title: Digital goods and markets: Emerging issues and challenges

paper_content:

This research commentary examines the changing landscape of digital goods, and discusses important emerging issues for IS researchers to explore. We begin with a discussion of the major technological milestones that have shaped digital goods industries such as music, movies, software, books, video games, and recently emerging digital goods. Our emphasis is on economic and legal issues, rather than on design science or sociological issues. We explore how research has been influenced by the major technological milestones and discuss the major findings of prior research. Based on this, we offer a roadmap for future researchers to explore the emergent changes in the digital goods arena, covering different aspects of digital goods industries such as risk management, value chain, legal aspects, transnational and cross-cultural issues.
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paper_title: Collaborative Micropayment Systems

paper_content:

Around the world many different micropayment systems are in use. Because of this variety, content providers and customers may rely on different systems. As a result, customers may be unable to buy content from providers using a different system. This paper proposes a novel approach that allows existing micropayment systems to collaborate. This collaboration is realized by introducing an intermediate system, called Payment Gateway, that interconnects different payment systems. This payment gateway enables content providers and customer to use their micropayment system of choice.
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paper_title: SEMOPS: design of a new payment service

paper_content:

One of the most promising future applications in the domain of mCommerce is the mobile payment. Different approaches come to the market and try to address existing needs, but up to day no global solution exists. In this paper we take an insight on the SEMOPS project, analyze some of the requirements that have been its guiding force as well as the business model it supports.
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Title: The Nuts and Bolts of Micropayments: A Survey

Section 1: INTRODUCTION
Description 1: In this section, introduce the topic of micropayments, discuss the reasons for renewed interest, and outline the contributions of this survey.

Section 2: BACKGROUND
Description 2: This section provides a definition of micropayments, discusses their properties, and traces the historical development of micropayment systems.

Section 3: A Short History of Micropayment Systems
Description 3: Summarize the different generations of micropayment systems and the innovations and shortcomings associated with each.

Section 4: CRYPTOGRAPHY-BASED SYSTEMS
Description 4: Discuss various cryptographic solutions for micropayments, classified into categories such as centralized solutions, voucher-based solutions, commitment-based systems, crypto-token solutions, probabilistic mechanisms, peer-to-peer systems, and enabling micropayments on Bitcoin.

Section 5: COMMERCIAL SOLUTIONS
Description 5: Examine commercial micropayment solutions, categorized by their different operational models including pre-paid systems, facilitating merchants, facilitating customers, and aggregation.

Section 6: OUTSTANDING CHALLENGES AND FUTURE DIRECTIONS
Description 6: Outline the key challenges in micromanagement system design and deployment, including security concerns, legal and ethical issues, cognitive costs, business models, and deployment strategies.

Section 7: CONCLUSION
Description 7: Summarize the survey, highlighting the current state of micropayment systems, the lessons learned from past implementations, and the future direction of research and development in this area.

Section 8: APPENDIX A: A PRIMER ON BUSINESS MODELS FOR WEB PUBLISHING
Description 8: Provide an overview of various business models for web publishing, including advertising, paywalls, and subscription-based models.

Section 9: APPENDIX B: STANDARDIZATION
Description 9: Discuss standardization efforts by organizations like the World Wide Web Consortium (W3C) and other industry groups aimed at developing universal micropayment protocols.