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An important current trend in advertising is the replacement of traditional pay-per-exposure (pay-perimpression) pricing models with performance-based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action (PPA) mechanisms are becoming the predominant method of selling advertising on the Internet. Well-known examples include pay-per- click, pay-per-call, and pay-per-sale. This work highlights an important, and hitherto unrecognized, side effect of PPA advertising. I find that, if the prices of advertised goods are endogenously determined by advertisers to maximize profits net of advertising expenses, PPA mechanisms induce firms to distort the prices of their goods (usually upward) relative to prices that would maximize profits in settings where advertising is sold under pay- per-exposure methods. Upward price distortions reduce both consumer surplus and the joint publisher advertiser profit, leading to a net reduction in social welfare. They persist in current auction-based ETA mechanisms, such as the ones used by Google, Yahoo!, and Microsoft. In the latter settings they also reduce publisher revenues relative to pay-per-exposure methods. I show that these phenomena constitute a form of double marginalization and discuss a number of enhancements to today's PPA mechanisms that restore equilibrium pricing of advertised goods to efficient levels, improving both consumer surplus as well as the publisher's expected profits. Key words: information systems; digital marketing; advertising; electronic markets and auctions; electronic commerce; sponsored search; keyword auctions History: Received March 21, 2010; accepted September 21, 2011, by Lorin Hitt, information systems. Published online in Articles in Advance March 9, 2012., Hail the money I spend on advertising is wasted; the trouble is, I don't know which half. --John Wanamaker, U.S. department store merchant 1. Introduction John Wanamaker's famous quote has [...]

Investment in defense by all agents is a socially optimum equilibrium in many interdependent security scenarios. However, practically, some agents might still choose not to invest in security due to bounded rationality and errors, thus decreasing the total social welfare. Previous work shows that providing subsidies may help induce more agents to invest. Our study suggests that giving subsidies to agents prone to making an erroneous choice could increase the stability of the socially optimum equilibrium, as well as decrease the total social costs., INTRODUCTION Homeland security has received a significant amount of attention since September 11, 2001 (Zhuang and Bier, 2007). Many security scenarios (e.g., Internet, transportation, and supply chain) involve interdependence among [...]

How should the information on the Internet be organized? This question and the possible solutions spark debates among people concerned with how we identify, classify, and retrieve Internet content. This [...]

Admission control plays a very important role in guaranteeing the quality-of-service (QoS) in wireless mesh networks (WMNs). In this paper, based on the channel and hidden terminal information, we first estimate the available bandwidth in the operation of medium access control (MAC). We then design an admission control algorithm (ACA) at the MAC layer to address the QoS issue for real-time and nonreal-time traffic. For real-time traffic, all nodes on a route make an admission control decision based on the estimated available bandwidth. For the nonreal-time traffic, a rate adaptation algorithm is proposed to adjust the sending rates of sources to prevent the network from entering the congestion state. Finally, through extensive simulations, we demonstrate the effectiveness of our algorithm. Index Terms--Admission control, medium access control (MAC), quality of service (QoS), wireless mesh networks (WMNs).

Wireless metropolitan area sharing networks (WMSNs) are wide-area wireless networks with nodes owned and managed by independent wireless Internet service providers (WISPs). To support seamless roaming in emerging WMSNs, in this paper, we propose a localized and distributed authentication and billing architecture that aims at enabling efficient and privacy-preserving mutual authentication between mobile users (MUs) and WISPs. User anonymity and identity privacy can be protected, even in the presence of collusion between WISPs and a roaming broker (RB), which is considered to be the strongest user privacy protection. An efficient billing architecture is introduced and performed in the same stage of roaming, where U-tokens are defined and can be purchased by MUs from an RB as authentication credentials for the MUs to access the wireless network. The WISPs, thus, can cash the collected U-tokens in the RB for payment. We show that the proposed authentication and billing architecture can support localized inter-WISP authentication through the divisible blind signature scheme and a local witness strategy. A detailed analysis on a number of performance metrics, such as computation time and power consumption, is given to validate the performance of the proposed architectures. Index Terms--Billing, partially blind signature, privacy protection, roaming, wireless metropolitan area sharing networks (WMSNs).

Mobile ad hoc networks (MANETs) are usually formed without any major infrastructure. As a result, they are relatively vulnerable to malicious network attacks, and therefore, security is a more significant issue than infrastructure-based wireless networks. In MANETs, it is difficult to identify malicious hosts as the topology of the network dynamically changes. A malicious host can easily interrupt a route for which it is one of the forming nodes in the communication path. In the literature, there are several proposals to detect such malicious hosts inside the network. In those methods, a baseline profile, which is defined as per static training data, is usually used to verify the identity and the topology of the network, thus preventing any malicious host from joining the network. Since the topology of a MANET dynamically changes, the mere use of a static baseline profile is not efficient. In this paper, we propose a new anomaly-detection scheme based on a dynamic learning process that allows the training data to be updated at particular time intervals. Our dynamic learning process involves calculating the projection distances based on multidimensional statistics using weighted coefficients and a forgetting curve. We use the network simulator 2 (ns-2) system to conduct the MANET simulations and consider scenarios for detecting five types of attacks. The simulation results involving two different networks in size show the effectiveness of the proposed techniques. Index Terms--Ad hoc on-demand distance vector (AODV), anomaly detection, dynamic learning, forgetting curve, malicious attacks, mobile ad hoc networks (MANETs), projection distance.

Two generic man-in-the middle attacks on Hypertext Transfer Protocol (HTTP) downloads are used to show how they can attack specific auto-updating processes in software packages. Some solutions to the problem are presented.

The Attack Diagnosis (AD), a novel attack mitigation scheme that adopts a divide-and-conquer strategy to throttle attack traffic generated in Distributed Denial-of-Service (DDoS) attacks, is described. AD consists of a repetitive process of isolating an attacker and filtering its traffic whereas Parallel Attack Diagnosis (PAD) can throttle traffic coming from multiple attackers simultaneously and both of them are found to be robust against Internet protocol (IP) spoofing with low false positive ratios.

A network is considered where users can issue certificates that identify the public keys of other users in the network. It is shown that the problem of computing optimal dispersal of a given set is NP-complete.

In a paper recently published in the IEEE TRANSACTIONS ON CONSUMER ELECTRONICS, Zhu and Ma proposed a new authentication scheme with anonymity for wireless environments. However, this paper shows that Zhu and Ma's scheme has some security weaknesses. Therefore, in this paper, a slight modification to their scheme is proposed to improve their shortcomings. As a result, the scheme proposed in this paper can enhance the security of Zhu and Ma's scheme. Finally, the performance of this scheme is analyzed. Compared with the Zhu-Ma scheme, this scheme is also simple and efficient. Index Terms--Anonymity, authentication, security, wireless network.

There is an urgent need for effective solutions against distributed denial-of-service (DDoS) attacks directed at many well-known Web sites. A probabilistic marking algorithm is presented in which one can quickly deduce the intensity of the local traffic generated at each router in the attack graph based on the volume of received marked packets at the victim site.

Using Sabatier's Advocacy Coalition Framework, the development of the Broadcasting Services Amendment (Online Services) Act 1999 is presented. Introduced to control the flow of online content (especially pornography) into and within Australia, this policy area incorporates a mix of high technology, morality and commercial interests. Analysis of the development of the Act is presented over five periods that show: the activation and formation of competing coalitions; acquisition of information and arguments about what form (if any) government regulation should take; and the relative importance of the issue. Analysis shows a number of relatively stable advocacy coalitions formed rapidly in response to government moves for regulation. The stability of these coalitions was significantly influenced by short-term changes in regulatory technology and the nature of the political discourse used by the government which raised or lowered the 'temperature' of subsystem conflict. The article makes a number of methodological comments about the application of multivariate clustering to subsystem analysis.

The dynamic evolvement or morphing and regeneration for competitive advantage of Yahoo! and Excite in the Internet are analyzed.

Customer privacy in electronic commerce has been the subject of lawsuits and government investigation. Stakeholders must offer a multilayered model of privacy for customers and make corporate commitment to retaining customer trust.

This article examines the political and financial aspects associated with the development of telecommunication infrastructure networks. The development of the information superhighway is explored through the Iowa Communications Network and the North Carolina Information Highway.

A discussion of Internet management in presented. Topics include the year two thousand computer transition, governance, domain name management, protocol standardization, and global communications.