Reputation Systems for Self-Organized Networks

Self-organized networks such as mobile ad-hoc, Internet-based peer-to-peer, wireless mesh and Fourth Generation (4G) Wireless networks depend on cooperation of nodes. Reputation systems help nodes decide with whom to cooperate and which nodes to avoid. They have been studied and applied almost separately in diverse disciplines such as economics, computer science and social science, resulting in effort duplication and inconsistent terminology. In this paper, we aim at bringing together these efforts by outlining features and fundamental questions common to reputation systems in general. We derive methodologies to address these questions and lessons for both reputation system design and research from our own experiences and evaluations by simulation and analytical modelling. We argue for using deviation tests, discounting, only passing on of first-hand information, secondary response, and stressing the importance of identity

A Multi Agent System for Flow-Based Intrusion Detection Using Reputation and Evolutionary Computation

The rising sophistication of cyber threats as well as the improvement of physical computer network properties present increasing challenges to contemporary Intrusion Detection (ID) techniques. To respond to these challenges, a multi agent system (MAS) coupled with flow-based ID techniques may effectively complement traditional ID systems. This paper develops: 1) a scalable software architecture for a new, self-organized, multi agent, flow-based ID system; and 2) a network simulation environment suitable for evaluating implementations of this MAS architecture and for other research purposes. Self-organization is achieved via 1) a reputation system that influences agent mobility in the search for effective vantage points in the network; and 2) multi objective evolutionary algorithms that seek effective operational parameter values. This paper illustrates, through quantitative and qualitative evaluation, 1) the conditions for which the reputation system provides a significant benefit; and 2) essential functionality of a complex network simulation environment supporting a broad range of malicious activity scenarios. These results establish an optimistic outlook for further research in flow-based multi agent systems for ID in computer networks

Firms, Courts, and Reputation Mechanisms: Towards a Positive Theory of Private Ordering

This Essay formulates a positive model that predicts when commercial parties will employ private ordering to enforce their agreements. The typical enforcement mechanism associated with private ordering is the reputation mechanism, in which a merchant community punishes parties in breach of contract by denying them future business. The growing private ordering literature argues that these private enforcement mechanisms can be superior to the traditional, less efficient enforcement measures provided by public courts. However, previous comparisons between public and private contractual enforcement have presented a misleading dichotomy by failing to consider a third enforcement mechanim: the vertically integrated firm. This Essay develops a model that comprehensively addresses three distinct types of enforcement mechanisms--firms, courts, and reputation-based private ordering. The model rests on a synthesis of transaction cost economics, which compares the efficiencies of firms versus markets, and the private ordering literature, which compares the efficiencies of public courts versus private ordering. It hypothesizes that private ordering will arise when agreements present enforcement difficulties, high-powered market incentives are important, and the costs of entry barriers are low. The Essay then conducts an illustrative test by comparing the model\u27s predictions to documented instances of private ordering

SecMon: End-to-End Quality and Security Monitoring System

The Voice over Internet Protocol (VoIP) is becoming a more available and popular way of communicating for Internet users. This also applies to Peer-to-Peer (P2P) systems and merging these two have already proven to be successful (e.g. Skype). Even the existing standards of VoIP provide an assurance of security and Quality of Service (QoS), however, these features are usually optional and supported by limited number of implementations. As a result, the lack of mandatory and widely applicable QoS and security guaranties makes the contemporary VoIP systems vulnerable to attacks and network disturbances. In this paper we are facing these issues and propose the SecMon system, which simultaneously provides a lightweight security mechanism and improves quality parameters of the call. SecMon is intended specially for VoIP service over P2P networks and its main advantage is that it provides authentication, data integrity services, adaptive QoS and (D)DoS attack detection. Moreover, the SecMon approach represents a low-bandwidth consumption solution that is transparent to the users and possesses a self-organizing capability. The above-mentioned features are accomplished mainly by utilizing two information hiding techniques: digital audio watermarking and network steganography. These techniques are used to create covert channels that serve as transport channels for lightweight QoS measurement's results. Furthermore, these metrics are aggregated in a reputation system that enables best route path selection in the P2P network. The reputation system helps also to mitigate (D)DoS attacks, maximize performance and increase transmission efficiency in the network.Comment: Paper was presented at 7th international conference IBIZA 2008: On Computer Science - Research And Applications, Poland, Kazimierz Dolny 31.01-2.02 2008; 14 pages, 5 figure

Privacy-preserving scheme for mobile ad hoc networks.

This paper proposes a decentralized trust establishment protocol for mobile ad hoc networks (MANETs), where nodes establish security associations. In order to achieve privacy and security, we use homomorphic encryption and polynomial intersection so as to find the intersection of two sets. The first set represents a list of recommenders of the initiator and the second set is a list of trusted recommenders of the responder. The intersection of the sets represents a list of nodes that recommend the first node and their recommendations are trusted by the second node. In our experimental results we show that our scheme is effective even if there are 30 trusted nodes

Norms and Law: Putting the Horse Before the Cart

Law and society scholars have long been fascinated with the interplay of formal legal and informal extralegal procedures. Unfortunately, the fascination has been accompanied by imprecision, and scholars have conceptually conflated two very different mechanisms that extralegally resolve disputes. One set of mechanisms might be described as the shadow of the law, made famous by seminal works by Professors Stewart Macaulay and Marc Galanter, in which social coercion and custom have force because formal legal rights are credible and reasonably defined. The other set of mechanisms, recently explored by economic historians and legal institutionalists, might be described as order without law, borrowing from Professor Robert Ellickson\u27s famous work.1 In this second mechanism, extralegal mechanisms—whether organized shunning, violence, or social disdain—replace legal coercion to bring social order and are an alternative to, not an extension of, formal legal sanctions. One victim of conflating these mechanisms has been our understanding of industry-wide systems of private law and private adjudication, or private legal systems. Recent examinations of private legal systems have chiefly understood those systems as efforts to economize on litigation and dispute-resolution costs, but private legal systems are better understood as mechanisms that economize on enforcement costs. This is not a small mischaracterization. Instead, it reveals a deep misunderstanding of when and why private enforcement systems arise in a modern economy. This Essay provides a taxonomy for the various mechanisms of private ordering. These assorted mechanisms, despite their important differences, have been conflated in large part because there has been a poor understanding of the particular institutional efficiencies and costs of the alternative systems. Specifically, enforcement costs have often been inadequately distinguished from procedural or disputeresolution costs, and this imprecision has produced theories that inaccurately predict when private ordering will thrive and when the costs of private ordering overwhelm corresponding efficiencies. The implications for institutional theory are significant, as confusion in the literature has led to overappreciation of private ordering, underappreciation of social institutions, and Panglossian attitudes toward both lawlessness and legal development