This book constitutes the refereed proceedings of the 12th International Conference on Decision and Game Theory for Security, GameSec 2021,held in October 2021. Due to COVID-19 pandemic the conference was held virtually.
The 20 full papers presented were carefully reviewed and selected from 37 submissions.

Computing Nash Equilibria in Multiplayer DAG-Structured Stochastic Games with Persistent Imperfect Information.- Two Algorithms for Computing Exact and Approximate Nash Equilibria in Bimatrix Games.- Separable Network Games With Compact Strategy Sets.- Countering Attacker Data Manipulation in Security Games.- Scalable Optimal Classifiers for Adversarial Settings under Uncertainty.- Learning Generative Deception Strategies in Combinatorial Masking Games.- Network Games with Strategic Machine Learning.- No Time To Lie: Bounds on the Learning Rate of a Defender for Inferring Attacker Target Preferences.- When Should You Defend Your Classifier? -- A Game-theoretical Analysis of Countermeasures against Adversarial Examples.- A Mechanism Design Approach to Solve Ransomware Dilemmas.- Winning the Ransomware Lottery.- Combating Ransomware in Internet of Things: A Games-in-Games Approach for Cross-Layer Cyber Defense and Security Investment.

GPSR Compliance The European Union's (EU) General Product Safety Regulation (GPSR) is a set of rules that requires consumer products to be safe and our obligations to ensure this. If you have any concerns about our products you can contact us on ProductSafety@springernature.com. In case Publisher is established outside the EU, the EU authorized representative is: Springer Nature Customer Service Center GmbH Europaplatz 3 69115 Heidelberg, Germany ProductSafety@springernature.com