A game-theoretic analysis of information security investment for multiple firms in a network

Abstract

The application of Internet of Things promotes the cooperation among firms, and it also introduces some information security issues. Due to the vulnerability of the communication network, firms need to invest in information security technologies to protect their confidential information. In this paper, considering the multiple-step propagation of a security breach in a fully connected network, an information security investment game among n firms is investigated. We make meticulous theoretic and experimental analyses on both the Nash equilibrium solution and the optimal solution. The results show that a larger network size (n) or a larger one-step propagation probability (q) has a negative effect on the Nash equilibrium investment. The optimal investment does not necessarily increase in n or q, and its variation trend depends on the concrete conditions. A compensation mechanism is proposed to encourage firms to coordinate their strategies and invest a higher amount equal to the optimal investment when they make decisions individually. At last, our model is extended by considering another direct breach probability function and another network structure, respectively. We find that a higher connection density of the network will result in a greater expected cost for each firm.

Keywords:

• IoT
• information security investment
• multiple-step propagation
• Nash equilibrium
• optimal solution

Acknowledgements

This work is supported by the National Nature Science Foundation of China (71231004, 71521001, 71601065, 71501058, 71131002), the Humanities and Social Sciences Foundation of the Chinese Ministry of Education (No. 15YJC630097), Nature Science Foundation of Anhui Province (1508085QG148, 1608085QG167), and the Fundamental Research Funds for the Central Universities of China (JZ2014HGQC0143). Panos M. Pardalos is partially supported by the project of “Distinguished International Professor by the Chinese Ministry of Education” (MS2014HFGY026).