Noisy data appear very naturally in applications where the authentication is based on physical identifiers. This book provides a self-contained overview of the techniques and applications of security based on noisy data. It covers both the theory of authentication based on noisy data and shows it in practice as a key tool for prevention of counterfeiting. Biometrics and physical unclonable functions are discussed extensively. Key new technologies discussed include: -Algorithms to derive secure keys form noisy data in particular from Physical Unclonable Functions and Biometrics, - also the theory which proves that those algorithms are secure is made accessible; Practical Implementations of the above mentioned algorithms; - Techniques that give insight in the security of those systems in practice; An overview and detailed description of new applications that become possible by using these new algorithms. This book can serve as a starting point for PhD students entering the field and will also benefit professionals.