Enrique de la Hoz

A REGION‐BASED MULTI‐ISSUE NEGOTIATION PROTOCOL FOR NONMONOTONIC UTILITY SPACES

Nonmonotonic utility spaces are found in multi‐issue negotiations where the preferences on the issues yield multiple local optima. These negotiations are specially challenging because of the inherent complexity of the search space and the difficulty of learning the opponent’s preferences. Most current solutions successfully address moderately complex preference scenarios, while solutions intended to operate in highly complex spaces are constrained by very specific preference structures. To overcome these problems, we propose the Region‐Based Multi‐issue Negotiation Protocol (RBNP) for bilateral automated negotiation. RBNP is built upon a nonmediated recursive bargaining mechanism which efficiently modulates a region‐based joint exploration of the solution space. We empirically show that RBNP produces outcomes close to the Pareto frontier in reasonable negotiation times, and show that it provides a significantly better performance when compared to a generic Similarity‐Based Multi‐issue Negotiation Protocol (SBNP), which has been successfully used in many negotiation models. We have paid attention to the strategic issues, proposing and evaluating several concession mechanisms, and analyzing the equilibrium conditions. Results suggest that RBNP may be used as a basis to develop negotiation mechanisms in nonmonotonic utility spaces.

The comparison of stigmergy strategies for decentralized traffic congestion control: preliminary results

We investigate several stigmergies models for decentralized traffic congestion control. For realizing a smart city, one of the main problems that should be handled is traffic congestion. There have been a lot of works on managing traffic congestion with information technology. There is a relatively long history on observing traffic flow and then providing stochastic estimation on traffic congestion. Recently, more dynamic coordination methods are becoming possible by using more short term traffic information. Short term traffic information can be provided by car navigation systems with GPS (Global Positioning System)s and probe-vehicle information. There are several approaches to handle short term traffic information, in which stigmergy-based approach is a popular. Stigmergy is employed for indirect communication for cooperation among distributed agents. We can imagine several types of stigmergies : long term memory, short term memory, and anticipatory memory. However, there have been no discussion what kind of stigmergies can work well for managing traffic congestion. We conducted several simulations to compare the different kind of stigmergies. Our preliminary results demonstrate that if the traffic network is static, the combination of long term and short term stigmergies overcome the other stigmergies.

Design and evaluation of a learning environment to effectively provide network security skills

Information system security and network security are topics of increasing importance in the information society. They are also topics where the adequate education of professionals requires the use of specific laboratory environments where the practical aspects of the discipline may be addressed. However, most approaches currently used are excessively static and lack the flexibility that the education requirements of security professionals demand. In this paper we present NEMESIS, a scenario generation framework for education on system and network security, which is based on virtualization technologies and has been designed to be open, distributed, modular, scalable and flexible. Finally, an example scenario is described and some results validating the benefits of its use in undergraduate computer security courses are shown.

Consensus policy based multi-agent negotiation

Multiagent negotiation may be understood as a consensus based group decision-making which ideally should seek the agreement of all the participants. However, there exist situations where an unanimous agreement is not possible or simply the rules imposed by the system do not seek such unanimous agreement. In this paper we propose to use a consensus policy based mediation framework (CPMF) to perform multiagent negotiations. This proposal fills a gap in the literature where protocols are in most cases indirectly biased to search for a quorum. The mechanisms proposed to perform the exploration of the negotiation space are derived from the Generalized Pattern Search non-linear optimization technique (GPS). The mediation mechanisms are guided by the aggregation of the agent preferences on the set of alternatives the mediator proposes in each negotiation round. Considerable interest is focused on the implementation of the mediation rules where we allow for a linguistic description of the type of agreements needed. We show empirically that CPMF efficiently manages negotiations following predefined consensus policies and solves situations where unanimous agreements are not viable.

Automated Negotiation for Resource Assignment in Wireless Surveillance Sensor Networks

Due to the low cost of CMOS IP-based cameras, wireless surveillance sensor networks have emerged as a new application of sensor networks able to monitor public or private areas or even country borders. Since these networks are bandwidth intensive and the radioelectric spectrum is limited, especially in unlicensed bands, it is mandatory to assign frequency channels in a smart manner. In this work, we propose the application of automated negotiation techniques for frequency assignment. Results show that these techniques are very suitable for the problem, being able to obtain the best solutions among the techniques with which we have compared them.

Detecting and defeating advanced man-in-the-middle attacks against TLS

TLS is an essential building block for virtual private networks. A critical aspect for the security of TLS dialogs is authentication and key exchange, usually performed by means of certificates. An insecure key exchange can lead to a man-in-the-middle attack (MITM). Trust in certificates is generally achieved using Public Key Infrastructures (PKIs), which employ trusted certificate authorities (CAs) to establish certificate validity chains.

An Infocard-Based Proposal for Unified Single Sign on

During last years, service federation has been a hot topic for researchers all along the world. In that context, single sign on (SSO) access to services has risen as a major concern for this kind of environments and many proposals suited to several scenarios have been stated. We can think of eduroam an eduGAIN as two major examples of this, the former as a federated initiative to provide access to network and the latter as a confederated proposal to provide secure access to web (and non-web as grid) resources. Given that both architectures usually are deployed in a common security domain, it could be interesting to explore ways to bring both worlds together, that is, to find a way to get access as we get access to the network services. Currently, there are two disjoint actions: first get access to network, with its own authentication process, and second get access to other resources through eduGAIN. The process could be greatly simplified if a way is devised to unify both accesses what has been called unified Single Sing On (uSSO). In this work, we propose a novel framework to provide uSSO in that environment with minor modifications to existing deployments employing Infocard Technology.

Negowiki : a set of community tools for the consistent comparison of negotiation approaches

There is a number of recent research lines addressing automated complex negotiations. Most of them focus on overcoming the problems imposed by the complexity of negotiation scenarios which are computationally intractable, be it by approximating these complex scenarios with simpler ones, or by developing heuristic mechanisms to explore more efficiently the solution space. The problem with these mechanisms is that their evaluation is usually restricted to very specific negotiation scenarios, which makes very difficult to compare different approaches, to re-use concepts from previous mechanisms to create new ones or to generalize mechanisms to other scenarios. This makes the different research lines in automated negotiation to progress in an isolated manner. A solution to this recurring problem might be to create a collection of negotiation scenarios which may be used to benchmark different negotiation approaches. This paper aims to fill this gap by providing a framework for the characterization and generation of negotiation scenarios intended to address this problem. The framework has been integrated in a website, called the Negowiki, which allows to share scenarios and experiment results with the negotiation community, facilitating in this way that researchers compare and share their advancements.

Trends in Multiagent Negotiation: From Bilateral Bargaining to Consensus Policies

Automated negotiation provides an important mechanism to reach agreements among distributed decision makers. It has been extensively studied from the perspective of e-commerce, though it can be seen from a more general perspective as a paradigm to solve coordination and cooperation problems in complex systems, e.g., task allocation, resource sharing, or surplus division. A variety of negotiation models have been proposed according to the many different parameters which may characterize a negotiation scenario. In this chapter, we briefly review the key concepts about multi-attribute negotiation and the most relevant works in the field, and then we focus on one of the more challenging topics on the field in the last few years, namely complex negotiations. In particular, we focus on situations where unanimous agreement is not possible or simply not desired, which is very common in negotiations involving complex, non-monotonic utility spaces. We describe a framework with which to perform multiagent negotiations where we can specify the type of agreements needed in terms of utility sharing among the agents. The proposed multi-round mediation process is based on the analysis of the agents’ offers at each negotiation round. At each round, the mediator applies Global Pattern Search (GPS) to the offers and then a linguistic expressed mediation rule based on Ordered Weighted Averaging Operators (OWA) that formalizes the consensus policy. At each round this mediation process generates a social contract that is submitted as feedback to the agents.

Using a scenario generation framework for education on system and internet security

Most approaches currently used for Education on Internet Security and Information System Security are excessively static and lack the flexibility that the education requirements of security professionals demand. They can greatly benefit from the use of specific laboratory environments. In this paper we show how a tool which allows to generate scenarios to be used in education on system and network security, based on virtualization technologies could be used to improve such scenarios because of its open, distributed, modular, scalable and flexible features. An example scenario is described and finally some results showing the benefits of its use in undergraduate computer security courses are shown.