Computer Science and Game Theory: A Brief Survey

There has been a remarkable increase in work at the interface of computer science and game theory in the past decade. In this article I survey some of the main themes of work in the area, with a focus on the work in computer science. Given the length constraints, I make no attempt at being comprehensive, especially since other surveys are also available, and a comprehensive survey book will appear shortly.Comment: To appear; Palgrave Dictionary of Economic

Decision-making and strategic thinking through analogies

When faced with a complex scenario, how does understanding arise in one’s mind? How does one integrate disparate cues into a global, meaningful whole? Consider the chess game: how do humans avoid the combinatorial explosion? How are abstract ideas represented? The purpose of this paper is to propose a new computational model of human chess intuition and intelligence. We suggest that analogies and abstract roles are crucial to solving these landmark problems. We present a proof-of-concept model, in the form of a computational architecture, which may be able to account for many crucial aspects of human intuition, such as (i) concentration of attention to relevant aspects, (ii) \ud how humans may avoid the combinatorial explosion, (iii) perception of similarity at a strategic level, and (iv) a state of meaningful anticipation over how a global scenario \ud may evolve

Network Formation Games under adversary attack with immunization: an introduction to the scientific research

En aquesta tesi de grau estudiem el model de Jocs de Formació de Xarxa amb atac i immunització introduït per Goyal et al. El model consta d'agents que volen maximitzar el benefici per connectar-se amb altres agents, fet que implica el cost de crear connexions. A més, un adversari atacarà la xarxa generada pels agents i els agents poden decidir immunitzar-se contra l'atac pagant un cost addicional. Goyal et al. van proposar diferents tipus d'adversaris. L'objectiu és comprendre el model enfocant-se a l'adversari d'atac aleatori i obtenir resultats de connectivitat, benestar social, diversitat de xarxes d'equilibri i dinàmiques de millor resposta basats en treballs previs. Pel que fa a l'adversari d'atac aleatori, demostrem que quan el cost de crear una aresta CE > 1 la xarxa d'equilibri no trivial (amb almenys una aresta i almenys un vèrtex immunitzat) resultant G és un graf connex, i quan CE i el cost de la immunització CI són constants i CE > 1, llavors el benestar de G és n^2-O(n^(5/3)). També estudiem la diversitat de xarxes d'equilibri i demostrem que entre els tipus de xarxes d'equilibri per l'adversari de màxima matança presentat per Goyal et al., graf nul, arbres, cicles, flors i graf bipartit complet també són equilibris per l'adversari d'atac aleatori amb lleugera diferència als paràmetres, les xarxes bosc tenen un cas particular d'equilibri per l'adversari d'atac aleatori però en general són només equilibri respecte a l'adversari de màxima matança. Finalment, estudiem la convergència de la dinàmica de millor resposta pel que fa a l'adversari d'atac aleatori i demostrem que pot ciclar. Concloem la nostra recerca amb una simulació de la dinàmica de millor resposta, observem que convergeix ràpidament a un equilibri eficient per l'adversari d'atac aleatori.In this bachelor thesis we study the Network Formation Games model with attack and immunization introduced by Goyal et al. The model consists of agents who want to maximize their benefit by connecting with other agents, which involves the cost of creating connections. Furthermore, an adversary will attack the network generated by agents and the agents can decide to immunize against the attack paying an additional cost. Different types of adversaries were proposed by Goyal et al. The objective is to gain an understanding of the model focusing on the random attack adversary and obtain results of connectivity, social welfare, diversity of equilibrium networks and best response dynamics based on previous works. With respect to the random attack adversary we prove that when cost of creating an edge CE > 1 the resulting non-trivial equilibrium network (with at least one edge and at least one immunized vertex) G is a connected graph, and when CE and cost of immunization CI are constants and CE > 1 then the welfare of G is n^2-O(n^(5/3)). We also study the diversity of equilibrium networks and we show that among the types of equilibrium networks for the maximum carnage adversary presented by Goyal et al., empty graph, trees, cycles, flowers and complete bipartite graph are also equilibria for the random attack adversary with slight difference in parameters, the forest networks have a particular case of equilibrium for the random attack adversary but in general they are only equilibrium with respect to the maximum carnage adversary. Finally, we study the convergence of the best response dynamics with respect to the random attack adversary and we prove that it can cycle. We conclude our research with a simulation of the best response dynamics, we observe that it converges rapidly to an efficient equilibrium for the random attack adversary

The future of Cybersecurity in Italy: Strategic focus area

This volume has been created as a continuation of the previous one, with the aim of outlining a set of focus areas and actions that the Italian Nation research community considers essential. The book touches many aspects of cyber security, ranging from the definition of the infrastructure and controls needed to organize cyberdefence to the actions and technologies to be developed to be better protected, from the identification of the main technologies to be defended to the proposal of a set of horizontal actions for training, awareness raising, and risk management

Computable Rationality, NUTS, and the Nuclear Leviathan

This paper explores how the Leviathan that projects power through nuclear arms exercises a unique nuclearized sovereignty. In the case of nuclear superpowers, this sovereignty extends to wielding the power to destroy human civilization as we know it across the globe. Nuclearized sovereignty depends on a hybrid form of power encompassing human decision-makers in a hierarchical chain of command, and all of the technical and computerized functions necessary to maintain command and control at every moment of the sovereign's existence: this sovereign power cannot sleep. This article analyzes how the form of rationality that informs this hybrid exercise of power historically developed to be computable. By definition, computable rationality must be able to function without any intelligible grasp of the context or the comprehensive significance of decision-making outcomes. Thus, maintaining nuclearized sovereignty necessarily must be able to execute momentous life and death decisions without the type of sentience we usually associate with ethical individual and collective decisions

Strategic Network Formation with Attack and Immunization

Strategic network formation arises where agents receive benefit from connections to other agents, but also incur costs for forming links. We consider a new network formation game that incorporates an adversarial attack, as well as immunization against attack. An agent's benefit is the expected size of her connected component post-attack, and agents may also choose to immunize themselves from attack at some additional cost. Our framework is a stylized model of settings where reachability rather than centrality is the primary concern and vertices vulnerable to attacks may reduce risk via costly measures. In the reachability benefit model without attack or immunization, the set of equilibria is the empty graph and any tree. The introduction of attack and immunization changes the game dramatically; new equilibrium topologies emerge, some more sparse and some more dense than trees. We show that, under a mild assumption on the adversary, every equilibrium network with $n$ agents contains at most $2n-4$ edges for $n\geq 4$. So despite permitting topologies denser than trees, the amount of overbuilding is limited. We also show that attack and immunization don't significantly erode social welfare: every non-trivial equilibrium with respect to several adversaries has welfare at least as that of any equilibrium in the attack-free model. We complement our theory with simulations demonstrating fast convergence of a new bounded rationality dynamic which generalizes linkstable best response but is considerably more powerful in our game. The simulations further elucidate the wide variety of asymmetric equilibria and demonstrate topological consequences of the dynamics e.g. heavy-tailed degree distributions. Finally, we report on a behavioral experiment on our game with over 100 participants, where despite the complexity of the game, the resulting network was surprisingly close to equilibrium.Comment: The short version of this paper appears in the proceedings of WINE-1