tailieunhanh - Modeling Internet Security Investments Tackling Topological Information Uncertainty

In this special feature, we examine how expected equity returns vary across a sample of globally active banks and over time in 11 countries. We estimate the determinants of the rate of return on bank stocks using a standard equity pricing framework that decomposes share price risk into a systematic and an idiosyncratic component. The systematic component cannot be diversified away, and it is priced in the market in the sense of commanding higher expected returns. The opposite holds for the idiosyncratic component, which can be diversified away in sufficiently large portfolios and hence is not priced in the. | Modeling Internet Security Investments Tackling Topological Information Uncertainty Ranjan Pal1 and Pan Hui2 1 University of Southern California USA rpal@ 2 Deutsch Telekom Laboratories Berlin Germany Abstract. Modern distributed communication networks like the Internet are characterized by nodes Internet users interconnected with one another via communication links. In this regard the security of individual nodes depend not only on their own efforts but also on the efforts and underlying connectivity structure of neighboring network nodes. By the term effort we imply the amount of investments made by a user in security mechanisms like antivirus softwares firewalls etc. to improve his security. However often due to the large magnitude of such networks it is not always possible for nodes to have complete effort and connectivity structure information about all their neighbor nodes. Added to this is the fact that in many applications the Internet users are selfish and are not willing to co-operate with other users on sharing effort information. In this paper we adopt a non-cooperative game-theoretic approach to analyze individual user security in a communication network by accounting for both the partial information that a network node possess about its underlying neighborhood connectivity structure and security investment of its neighbors as well as the presence of positive externalities arising from efforts exerted by neighboring nodes. We analyze the strategic interactions between Internet users on their security investments in order to investigate the equilibrium behavior of nodes and show i the existence of monotonic symmetric Bayesian Nash equilibria of efforts and ii better connected Internet users choose lower efforts to exert but earn higher utilities than less connected peers with respect to security improvement when user utility functions exhibit strategic substitutes are submodular. Our results extend previous work with .