6G is the next frontier in mobile communication, with development of 6G standards slated to begin as early as 2026. As telecommunications networks become even faster and more intelligent, security and privacy concerns will become all the more critical. In an increasingly connected world, there is an urgent need for user data to be safeguarded and system security enhanced against a new generation of threats. this book provides a comprehensive survey of these threats and the emerging techniques for safeguarding against them.