With the proliferation of biometric technology such as face, fingerprint, iris and voice recognition, concerns have arisen regarding the vulnerability of our biometric data. How can we safeguard our irreplaceable biometric data, which are intricately linked to our biological identities, from potential compromise? In the “Handbook of Biometric Template Protection,” we delve into the rapidly evolving world of Biometric Template Protection (BTP), which strives to mitigate the risks associated with the storage and usage of biometric templates (i.e., features that encode our biometric characteristics). This book presents a comprehensive overview of the BTP research field in three main parts. Firstly, it explores the importance of BTP in light of the dangers posed by compromised templates, the limitations of generic data protection mechanisms, and the need to adhere to privacy regulations. Secondly, it examines a number of different BTP methods, including handcrafted and learned techniques. Lastly, it discusses evaluation metrics used to assess the robustness of BTP methods. Each chapter includes study questions to encourage the reader to reflect on the content and deepen their understanding. Whether you are a newcomer to the BTP field, a seasoned researcher, or a practitioner wishing to deploy BTP in real-world biometrics applications, this book offers valuable insights into BTP’s critical role in safeguarding our identities. You will come away with not only a firm grasp of the fundamental concepts, but with inspiration to further advance biometric template protection to ensure more responsible use of biometric data in practice. With the proliferation of biometric technology such as face, fingerprint, iris and voice recognition, concerns have arisen regarding the vulnerability of our biometric data. How can we safeguard our irreplaceable biometric data, which are intricately linked to our biological identities, from potential compromise? In the “Handbook of Biometric Template Protection,” we delve into the rapidly evolving world of Biometric Template Protection (BTP), which strives to mitigate the risks associated with the storage and usage of biometric templates (i.e., features that encode our biometric characteristics). This book presents a comprehensive overview of the BTP research field in three main parts. Firstly, it explores the importance of BTP in light of the dangers posed by compromised templates, the limitations of generic data protection mechanisms, and the need to adhere to privacy regulations. Secondly, it examines a number of different BTP methods, including handcrafted and learned techniques. Lastly, it discusses evaluation metrics used to assess the robustness of BTP methods. Each chapter includes study questions to encourage the reader to reflect on the content and deepen their understanding. Whether you are a newcomer to the BTP field, a seasoned researcher, or a practitioner wishing to deploy BTP in real-world biometrics applications, this book offers valuable insights into BTP’s critical role in safeguarding our identities. You will come away with not only a firm grasp of the fundamental concepts, but with inspiration to further advance biometric template protection to ensure more responsible use of biometric data in practice. Dr Vedrana Krivokuća Hahn obtained her PhD degree in Computer Systems Engineering at the University of Auckland (New Zealand), on the topic of biometric template protection for fingerprints. She now works as a researcher in the Biometrics Security and Privacy Group at Idiap Research Institute (Switzerland), where she leads research on Biometric Template Protection (BTP), including the development of BTP methods and robust evaluation strategies for practical BTP implementations. Vedrana is currently the chief researcher in the Innosuisse PRiMEAiD project, which aims to apply BTP towards the development of a privacy-preserving face identification system for humanitarian aid distribution programmes. Vedrana also manages projects (both academic and industrial) on different biometrics topics, such as presentation attack detection (e.g., for the EU research project SOTERIA, on secure personal data platforms) and multimodal biometric recognition in vehicles (for an industrial partner). Vedrana is additionally involved in biometric system evaluations for industry and government applications, and is currently part of the EU CERTAIN project on AI system certification. She also engages in teaching activities, including the biometrics course as part of Idiap’s Masters in Artificial Intelligence programme, and public tutorials. Prof. Marta Gomez-Barrero is Full Professor for machine learning at the Universität der Bundeswehr München since 2023, head of the BioML: Biometrics and Machine Learning research group. She is general chair of the BIOSIG conference and has served for several conferences (e.g., IJCB, IWBF, EUSIPCO, WIFS, ICASSP) and journals (e.g., IEEE TIFS, IEEE TPAM