Inherent Game Characteristics of Electronic Negotiations

Negotiation activities have often been referred to as a game. For example, negotiators dance around each other, play with different strategies, follow rules and protocols, decide on particular moves from a set of alternatives, and try to achieve the ultimate goal of agreement. This paper presents the results of an explorative literature study examining the inherent game characteristics of electronic negotiations. To consider the context of information system explicitly, we analyse e-negotiations conducted in negotiation support systems. Our results reveal among others a strong social interaction element, various levels of difficulties and challenges, different activity choices that may lead to the same goal and continual feedback during these activities. With respect to current IS trends such as serious games and gamification, these identified game characteristics may serve as a basis for a gamified negotiation support system

Accelerating zero knowledge proofs

Les proves de coneixement zero són una eina criptogràfica altament prometedora que permet demostrar que un predicat és correcte sense revelar informació addicional sobre aquest. Aquestes tipus de proves són útils en aplicacions que requereixen tant integritat computacional com privadesa, com ara verificar la correcció dels resultats d'una computació delegada a una altra entitat, on hi poden haver involucrats valors d'entrada confidencials. Tanmateix, té un impediment que obstaculitza la seva adopció pràctica: el procés potencialment lent de generació de les proves. Així doncs, aquest projecte explora la viabilitat d'accelerar les proves de coneixement zero mitjançant hardware, amb l'objectiu de superar aquest obstacle crític.Las pruebas de conocimiento cero representan una herramienta criptográfica altamente prometedora que permite demostrar la corrección de un predicado sin revelar información adicional. Estas pruebas son útiles en aplicaciones que requieren tanto integridad computacional como privacidad, como por ejemplo la validación de los resultados de una computación delegada a otra entidad, donde pueden estar involucrados valores de entrada confidenciales. Sin embargo, existe un desafío significativo que obstaculiza su adopción práctica: el proceso potencialmente lento de generación de pruebas. Como resultado, este proyecto explora la viabilidad de acelerar las pruebas de conocimiento cero utilizando hardware, con el objetivo de superar este obstáculo crítico.Zero-knowledge proofs represent a highly promising cryptographic tool that enables the validation of a statement's correctness without revealing any supplementary information. These proofs find utility in applications demanding both computational integrity and privacy, such as validating outsourced computation results, where confidential input values may be involved. However, a significant challenge hinders their practical adoption: the potentially time-consuming process of generating proofs. Consequently, this project investigates the feasibility of accelerating zero-knowledge proofs using hardware, aiming to overcome this critical hurdle.Outgoin

mWater prototype #3 review

mWater is a software demonstrator developed in the Agreement Technologies Project. It is a Multi-Agent System (MAS) application that implements a market for water rights, including the model and simulation of the water-right market itself, the basin, users, protocols, norms and grievance situations. mWater is motivated due to the fact that water scarcity is becoming a major concern in most countries, not only because it threatens the economic viability of current agricultural practices, but because it is likely to alter an already precarious balance among its different types of use.Garrido Tejero, A.; Botti Navarro, VJ.; Giret Boggino, AS.; Alfonso Espinosa, B.; Noriega, P. (2013). mWater prototype #3 review. http://hdl.handle.net/10251/3181

Logiques pour la représentation et la conception d'enchères

Une enchère est un mécanisme compétitif qui permet d’allouer un ensemble de ressources auprès d’un ensemble d’agents. Ce mécanisme agrège les offres effectuées par les participants à l’enchère dans le but de produire une décision sociale caractérisée en termes d'allocations et de paiements. Les agents automatisés sont largement utilisés sur les marchés basés sur les enchères, mais ils sont généralement conçus pour agir dans un contexte spécifique. Pour passer d'un type de marché à un autre, les agents doivent être capables de "comprendre" les règles de l'enchère et de raisonner sur leurs valuations ainsi que sur les valeurs privées des autres joueurs. De fait, il est nécessaire de définir un langage simple permettant de représenter les règles d'un marché aux enchères, qui permettra ensuite à des joueurs généraux automatiques de raisonner stratégiquement dans différents environnements. Cet aspect stratégique, notion centrale de la théorie des jeux et des systèmes multi-agents, est de première importance dans la caractérisation des mécanismes d’enchères. Un problème de première importance concerne la conception de nouvelles enchères, ou plus généralement, de nouveaux mécanismes. En effet, un des principaux objectifs consiste à agréger les offres individuelles tout en garantissant un résultat socialement souhaitable. La dimension stratégique est donc au cœur de la conception de mécanismes. Alors que les langages logiques ont été largement considérés dans le contexte des Systèmes Multi-Agents (SMA), l'utilisation de méthodes formelles et de raisonnement stratégique pour la Conception Automatique de Mécanismes a été à peine étudiée. Cette thèse explore l'application des logiques pour la description et la conception de mécanismes d’enchères. Ces derniers placent la dimension stratégique en leur cœur et nous proposons l'utilisation de méthodes formelles pour la spécification, la conception et l'évaluation de mécanismes intégrant cette dimension. Dans un premier temps, afin de fournir une fondation pour les joueurs d'enchères généraux et automatisés dans les SMA, nous proposons un formalisme pour représenter les enchères, appelé Auction Description Language (ADL). ADL traite des dimensions importantes des marchés basés sur des enchères et est suffisamment général pour représenter la plupart des contextes d'enchères. Nous montrons qu’en enrichissant ADL avec un opérateur de connaissance et une modalité d'action pour caractériser le comportement rationnel limité des enchérisseurs, les agents enchérisseurs peuvent raisonner sur l'effet des actions ainsi que sur la rationalité des autres agents. Dans un second temps, nous proposons une nouvelle approche pour le raisonnement et la conception de nouvelles enchères basée sur des méthodes formelles. Cette approche vise à générer des mécanismes à partir de leurs spécifications et à les vérifier par rapport à des propriétés économiques objectives. Nous proposons une nouvelle variante de Strategy Logic (SL) avec une sémantique quantitative et des opérateurs épistémiques. Nous montrons comment elle permet d'exprimer des concepts essentiels de la théorie de l'économie, notamment l'équilibre de Nash et la manipulation stratégique, qui sont de première importance lors de la conception de nouvelles enchères et lorsque les agents doivent raisonner sur leurs propriétés. Nous introduisons aussi SL avec des stratégies naturelles, qui permet de raisonner sur les mécanismes en fonction de la complexité des stratégies. L'analyse des mécanismes et des stratégies se résume donc à la vérification de formule en SL dans des modèles représentant des enchères. Enfin nous proposons la reformulation du problème de la conception de mécanismes en termes de synthèse de spécifications logiques. Cette approche permet de générer automatiquement des mécanismes optimaux à partir d'une spécification, qui peut inclure non seulement les règles du jeu mais aussi des exigences sur le comportement stratégique des participants.An auction is a popular mechanism that aggregates participants' bids into a social decision, usually expressed in terms of allocations and payments. Automated agents are widely used in auction-based markets, but they are usually designed to act on a specific context. Those agents cannot switch between different kinds of markets. For doing so, they should be able to ``understand'' the auction rules and reason about their own valuations and about other players’ private information valuations. This limitation inspires the development of a lightweight logic-based language for representing the rules of an auction market, which will then allow automated general players to reason strategically in different environments. Another important problem is the design of new auctions and, more generally, mechanisms. The challenge here is to aggregate individual preferences, while choosing a socially desirable outcome and reaching an equilibrium even though agents can lie about their preferences. Although logic-based languages have been widely considered in the context of Multi-Agent Systems (MAS), the use of formal methods and strategic reasoning for Automated Mechanism Design (AMD) has not been much explored yet. This thesis investigates an application of logics and strategic reasoning for Game Theory and MAS. In particular, we propose the use of formal methods for the specification, design and evaluation of mechanisms, with focus on auctions. This thesis addresses such challenges by introducing logic-based approaches for representing and designing auction-based markets with strategic players. Firstly, for providing a foundation for general and automated auction playing in MAS, we propose a framework for representing auctions, denoted Auction Description Language (ADL). ADL addresses important dimensions of auction-based markets and is general enough to represent most auction settings. We illustrate the generality of ADL by modeling a number of representative auctions. We extend ADL with knowledge operators and an action modality for characterizing bounded rational behavior of bidders when reasoning about the effect of actions and other agents' rationality. Second, we propose a novel approach for reasoning and designing new auctions (and, in general, preference aggregation mechanisms) based on formal methods. Such approach for AMD aims to automatically generate mechanisms from their specifications and verify them in relation to target economical properties. For verifying mechanisms, we propose a new variant of Strategy Logic (SL) with quantitative semantics and epistemic operators. We demonstrate how it can express key concepts from Economic Theory, including Nash equilibrium, strategyproofness and individual rationality, which are at first importance when designing new auctions and when agents need to reason about their properties. We also introduce a quantitative semantics for SL with natural strategies and imperfect information which enables reasoning about mechanisms based on the complexity of strategies. The analysis of mechanisms and their strategies boils-down to model checking formulas from those SL variants. Finally, we offer a novel perspective on the design of mechanisms by rephrasing the AMD problem in terms of synthesis from specifications in Quantitative SL. This approach enables automatically generating optimal mechanisms from a quantitative logical specification, which may include not only game rules but also requirements over the strategic behavior of participants and quality of the outcome

An Argumentation-Driven Model for Flexible and Efficient Persuasive Negotiation

The purpose of this paper is to propose a formal description and implementation of a negotiation protocol between autonomous agents using persuasive argumentation. This protocol is designed to be simple and computationally efficient. The computational efficiency is achieved by specifying the protocol as a set of simple logical rules that software agents can easily combine. These latter are specified as a set of computational dialogue games about which agents can reason. The protocol converges by checking the termination conditions. The paper discusses the formal properties of the protocol and addresses, as proof of concept, the implementation issues using an agent-oriented platform equipped with logical programming mechanisms

Foundations of Software Science and Computation Structures

This open access book constitutes the proceedings of the 23rd International Conference on Foundations of Software Science and Computational Structures, FOSSACS 2020, which took place in Dublin, Ireland, in April 2020, and was held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2020. The 31 regular papers presented in this volume were carefully reviewed and selected from 98 submissions. The papers cover topics such as categorical models and logics; language theory, automata, and games; modal, spatial, and temporal logics; type theory and proof theory; concurrency theory and process calculi; rewriting theory; semantics of programming languages; program analysis, correctness, transformation, and verification; logics of programming; software specification and refinement; models of concurrent, reactive, stochastic, distributed, hybrid, and mobile systems; emerging models of computation; logical aspects of computational complexity; models of software security; and logical foundations of data bases.

Foundations of Software Science and Computation Structures

This open access book constitutes the proceedings of the 23rd International Conference on Foundations of Software Science and Computational Structures, FOSSACS 2020, which took place in Dublin, Ireland, in April 2020, and was held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2020. The 31 regular papers presented in this volume were carefully reviewed and selected from 98 submissions. The papers cover topics such as categorical models and logics; language theory, automata, and games; modal, spatial, and temporal logics; type theory and proof theory; concurrency theory and process calculi; rewriting theory; semantics of programming languages; program analysis, correctness, transformation, and verification; logics of programming; software specification and refinement; models of concurrent, reactive, stochastic, distributed, hybrid, and mobile systems; emerging models of computation; logical aspects of computational complexity; models of software security; and logical foundations of data bases.

Dialogue games and trust for communicating agents

Multi-agent applications are primarily based on agent interactions, which are constrained by the trust of participating agents. Two important issues in these applications are how agents can communicate in a flexible and efficient way and how an agent can authenticate information conveyed by other agents in the system. In this thesis, we present a new communication framework and trust model addressing these issues by considering three factors. The first factor is about the flexibility, complexity, soundness, and completeness of the communication protocol. The second factor is about the classification of agents from a trust point of view using direct interactions. The third factor is related to the categorization of the agent's chains through which the information is transmitted. Such a categorization is based upon the reliability of the agents in the chain. The model aims to examine all available data in order to determine the trustworthiness of agents as transmitters of information. This approach is the first attempt in multi-agent systems towards classifying agents in order to accomplish trust. We also propose a thorough set of criteria and policies to assign different degrees of trustworthiness to each agent and consequently to the chains in which they appear. Agents are considered autonomous and they interact flexibly using a set of logical rules called dialogue games. Termination, soundness, and completeness results of the communication protocol are proven and its computational complexity is addressed. The proposed approach is also evaluated. Keywords: Trust, Dialogue Games, Multi-Agent Systems, Agent Types, Agent Characteristics, Chain of Agent

Broker-based service-oriented content adaptation framework

Electronic documents are becoming increasingly rich in content and varied in format and structure. At the same time, user preferences vary towards the contents and their devices are getting increasingly varied in capabilities. This mismatch between rich contents and user preferences along with the end device capability presents a challenge in providing ubiquitous access to these contents. Content adaptation is primarily used to bridge the mismatch by providing users with contents that is tailored to the given contexts e.g., device capability, preferences, or network bandwidth. Existing content adaptation systems employing these approaches such as client-side, server-side or proxy-side adaptation, operate in isolation, often encounter limited adaptation functionality, get overload if too many concurrent users and open to single point of failure, thus limiting the scope and scale of their services. To move beyond these shortcomings, this thesis establishes the basis for developing content adaptation solutions that are efficient and scalable. It presents a framework to enable content adaptation to be consumed as Web services provided by third-party service providers, which is termed as “service-oriented content adaptation”. Towards this perspective, this thesis addresses five key issues – how to enable content adaptation as services (serviceoriented framework); how to locate services in the network (service discovery protocol); how to select best possible services (path determination); how to provide quality assurance (service level agreement (SLA) framework); and how to negotiate quality of service (QoS negotiation). Specifically, we have: (i) identified the key research challenges for service-oriented content adaptation, along with a systematic understanding of the content adaptation research spectrum, captured in a taxonomy of content adaptation systems; (ii) developed an architectural framework that provides the basis for enabling content adaptation as Web services, providing the facilities to serve clients’ content adaptation requests through the client-side brokering; (iii) developed a service discovery protocol, by taking into account the searching space, searching time, match type of the services and physical location of the service providers; (iv) developed a mechanism to choose the best possible combination of services to serve a given content adaptation request, considering QoS levels offered; (v) developed an architectural framework that provides the basis for managing quality through the conceptualization of service level agreement; and (vi) introduced a strategy for QoS negotiation between multiple brokers and service providers, by taking into account the incoming requests and server utilization and, thus requiring the basis of determining serving priority and negotiating new QoS levels. The performance of the proposed solutions are compared with other competitive solutions and shown to be substantially better