In recent years the rising complexity of Internet of Things IoT systems has increased their potential vulnerabilities and introduced new cybersecurity challenges. In this context state of the artampampnbspmethods and technologies for security risk assessment have prominent limitations when it comes to large scale cyberphysical and interconnected IoT systems. Risk assessments for modern IoT systems must be frequent dynamic and driven by knowledge about both cyber and physical assets.ampampnbsp Furthermore they should be more proactive more automated and able to leverage information shared across IoT value chains.This book introduces a set of novel risk assessment techniques and their role in the IoT Security risk management process.