A super-peer is a node in a peer-to-peer network that operates both as a server to a set of clients, and as an equal in a network of super-peers. Super-peer networks strike a balance between the efficiency of centralized search, and the autonomy, load balancing and robustness to attacks provided by distributed search. Furthermore, they take advantage of the heterogeneity of capabilities (e.g., bandwidth, processing power) across peers, which recent studies have shown to be enormous. Hence, new and old P2P systems like KaZaA and Gnutella are adopting super-peers in their design. Despite their growing popularity, the behavior of super-peer networks is not well understood. For example, what are the potential drawbacks of super-peer networks? How can super-peers be made more reliable? How many clients should a super-peer take on to maximize efficiency? we examine super-peer networks in detail, gaming an understanding of their fundamental characteristics and performance tradeoffs. We also present practical guidelines and a general procedure for the design of an efficient super-peer network.

Designing an Super-Peer Network

This chapter is devoted to a more detailed examination of game theory. Game theory is an important tool for analyzing strategic behavior, is concerned with how individuals make decisions when they recognize that their actions affect, and are affected by, the actions of other individuals or groups. Strategic behavior recognizes that the decision-making process is frequently mutually interdependent. Game theory is the study of the strategic behavior involving the interaction of two or more individuals, teams, or firms, usually referred to as players. Two game theoretic scenarios were examined in this chapter: Simultaneous-move and multi-stage games. In simultaneous-move games the players effectively move at the same time. A normal-form game summarizes the players, possible strategies and payoffs from alternative strategies in a simultaneous-move game. Simultaneous-move games may be either noncooperative or cooperative. In contrast to noncooperative games, players of cooperative games engage in collusive behavior. A Nash equilibrium, which is a solution to a problem in game theory, occurs when the players’ payoffs cannot be improved by changing strategies. Simultaneous-move games may be either one-shot or repeated games. One-shot games are played only once. Repeated games are games that are played more than once. Infinitely-repeated games are played over and over again without end. Finitely-repeated games are played a limited number of times. Finitely-repeated games have certain or uncertain ends.

An Introduction to Game Theory

Microsoft has promoted ASP.NET’s new web services more than almost any other part of the.NET Framework. But despite their efforts, confusion is still widespread about what a web service is and, more importantly, what it’s meant to accomplish. This chapter introduces web services and explains their role in Microsoft’s vision of the programmable web. Along the way, you’ll learn about the open standards plumbing that allows web services to work and removes some of the confusion surrounding technical terms like WSDL (Web Service Description Language), SOAP, and UDDI (universal description, discovery, and integration).

Web Services Architecture

Satellite communications (SatComs) have recently entered a period of renewed interest motivated by technological advances and nurtured through private investment and ventures. The present survey aims at capturing the state of the art in SatComs, while highlighting the most promising open research topics. Firstly, the main innovation drivers are motivated, such as new constellation types, on-board processing capabilities, non-terrestrial networks and space-based data collection/processing. Secondly, the most promising applications are described, i.e., 5G integration, space communications, Earth observation, aeronautical and maritime tracking and communication. Subsequently, an in-depth literature review is provided across five axes: i) system aspects, ii) air interface, iii) medium access, iv) networking, v) testbeds & prototyping. Finally, a number of future challenges and the respective open research topics are described.

/pdf/satellite-communications-in-the-new-space-era-a-survey-and-13ge69opzh.pdf

Satellite Communications in the New Space Era: A Survey and Future Challenges

Vehicular ad hoc networks (VANETs) have stimulated interest in both academic and industry settings because, once deployed, they would bring a new driving experience to drivers. However, communicating in an open-access environment makes security and privacy issues a real challenge, which may affect the large-scale deployment of VANETs. Researchers have proposed many solutions to these issues. We start this paper by providing background information of VANETs and classifying security threats that challenge VANETs. After clarifying the requirements that the proposed solutions to security and privacy problems in VANETs should meet, on the one hand, we present the general secure process and point out authentication methods involved in these processes. Detailed survey of these authentication algorithms followed by discussions comes afterward. On the other hand, privacy preserving methods are reviewed, and the tradeoff between security and privacy is discussed. Finally, we provide an outlook on how to detect and revoke malicious nodes more efficiently and challenges that have yet been solved.

A Security and Privacy Review of VANETs

https://comunidad.udistrital.edu.co/malzate/files/2011/12/AGameTheoreticTrustModelOfCooperation.pdf

A game theoretic trust model for on-line distributed evolution of cooperation inMANETs

EPA: An efficient and privacy-aware revocation mechanism for vehicular ad hoc networks

Purpose – Mobile ad hoc networks rely on cooperation to perform essential network mechanisms such as routing. Therefore, network performance depends to a great extent on giving participating nodes an incentive for cooperation. The level of trust among nodes is the most frequently used parameter for promoting cooperation in distributed systems. There are different models for representing trust, each of which is suited to a particular context and leads to different procedures for computing and propagating trust. The goal of this study is to analyze the most representative approaches for mobile ad hoc networks. It aims to obtain a qualitative comparison of the modeling approaches, according to the three basic components of a trust model: information gathering, information scoring and ranking, and action execution.Design/methodology/approach – The paper identifies the different tasks required by a trust system and compares the way they are implemented when the system model itself is based on information theor...

A review of trust modeling in ad hoc networks

Public-key cryptography is widely used to provide Internet security services. The public-key infrastructure (PKI) is the infrastructure that supports the public-key cryptography, and the revocation of certificates implies one of its major costs. The goal of this article is to explain in detail a certificate revocation system based on the Merkle hash tree (MHT) called AD---MHT. AD---MHT uses the data structures proposed by Naor and Nissim in their authenticated dictionary (AD) [20]. This work describes the tools used and the details of the AD---MHT implementation. The authors also address important issues not addressed in the original AD proposal, such as responding to a request, revoking a certificate, deleting an expired certificate, the status checking protocol for communicating the AD---MHT repository with the users, verifying a response, system security, and, finally, performance evaluation.

https://link.springer.com/content/pdf/10.1007%2Fs10207-003-0026-4.pdf

Oscar Esparza

Papers

A game theoretic trust model for on-line distributed evolution of cooperation inMANETs

EPA: An efficient and privacy-aware revocation mechanism for vehicular ad hoc networks

A review of trust modeling in ad hoc networks

Certificate revocation system implementation based on the Merkle hash tree

PPREM: Privacy Preserving REvocation Mechanism for Vehicular Ad Hoc Networks