It is impossible to overstate the importance of America's cyber infrastructure to our individual welfare and national security. Yet, cybercrime is rampant. Critical systems are vulnerable to malicious forms of electronic intrusion and interference. The U.S. is both the source and target of international cyber aggression. How the U.S. responds to these challenges depends partly on questions within the specialized domain of scientists and engineers. But questions of policy, well within the understanding of non-expert citizens, also loom large—and the public, by and large, is not discussing them. Cybersecurity: Shared Risks, Shared Responsibilities aims to make key issues accessible to a broad readership. Experts in law, business, public policy, information and computer science, and national security have joined in this volume to stimulate an informed public dialogue that moves past political shibboleths and toward a nuanced understanding of the cybersecurity challenge and the tradeoffs entailed in formulating a sensible national response.