This comprehensive work focuses on the current state of play regarding cyber security threats to government and business, which are imposing unprecedented costs and disruption. At the same time, it also takes a forward-looking approach to such emerging industries as automobiles and appliances, the operations of which are becoming more closely tied to the internet. Revolutionary developments will have security implications unforeseen by manufacturers, and the authors explore these in detail, drawing on lessons worldwide to show how nations and businesses can combat these threats. The first section describes existing threats and their consequences. The second section identifies newer cyber challenges across an even broader spectrum, including the internet of things. The concluding section looks at policies and practices in the US, UK, and elsewhere that offer ways to mitigate threats to cyber security. For policymakers, business leaders, cyber security experts, and general readers.