Beyond Fear: Thinking Sensibly About Security in an Uncertain World is a non-fiction book by Bruce Schneier, published in 2003. The book grew out of an Atlantic Monthly article by Charles Mann. Beyond Fear presents a five-step process for evaluating the value of a countermeasure against security attacks. The book is divided into three parts. Part one of Beyond Fear introduces the idea that all security involves "trade-offs". Part two: "How Security Works", explains key principles in security such as Attackers, Defenders, Identification, Authentication, and Authorization. Part three: "The Game of Security" ties all the issues together and offers suggestions on how to form a coherent security policy.
This book is about security: how it works and how to think about it. It's not about whether a particular security measure works, but about how to analyze and evaluate security measures.
— Schneier's description of Beyond Fear (ch.1, pg.7)