Biometric template security is a critical area of research in biometric recognition systems, where the primary concern is protecting the sensitive biometric data stored in templates. This dissertation explores the vulnerabilities of biometric systems, particularly those related to the storage and protection of biometric templates. It highlights the risks associated with the potential compromise of biometric templates, which can lead to unauthorized access and privacy violations. The research demonstrates that fingerprint images can be reconstructed from known fingerprint representations, such as Minutiae Cylinder Codes, with high accuracy, which can be used to create spoof fingers and compromise biometric systems. The dissertation categorizes techniques for safeguarding biometric templates into two main groups: biometric cryptosystems and template transformation techniques. Biometric cryptosystems bind secure keys to biometric data to create secure sketches that cannot be used to recover the original data or the key. Template transformation techniques non-invertibly transform biometric templates using the user's password. The research analyzes and improves these techniques, focusing on fuzzy vault and fuzzy commitment, which are used to secure templates represented as points or binary vectors, respectively. An improved security analysis is provided, considering the non-uniform distribution of biometric features. The dissertation also proposes a framework to effectively combine multiple biometric representations and evaluates various template transformation techniques using comprehensive metrics. The analysis of template inversion, or the recovery of the original template from a transformed one, is a key element of security analysis. The research develops techniques for template inversion and evaluates the security of two different transformed templates: one based on point set representation and the other on binary vector representation. The analysis indicates that while these techniques are generally considered secure, they are vulnerable to inversion attacks. The protection of biometric templates is crucial for public acceptance, as the potential compromise of system security and user privacy is significant. The dissertation emphasizes the importance of rigorous analysis of the security provided by techniques used to protect biometric templates. It concludes that the security analysis presented will help streamline the development of new techniques and lead to a robust solution for protecting biometric data. The research also acknowledges the contributions of various individuals and institutions that supported the work, including advisors, committee members, and colleagues.Biometric template security is a critical area of research in biometric recognition systems, where the primary concern is protecting the sensitive biometric data stored in templates. This dissertation explores the vulnerabilities of biometric systems, particularly those related to the storage and protection of biometric templates. It highlights the risks associated with the potential compromise of biometric templates, which can lead to unauthorized access and privacy violations. The research demonstrates that fingerprint images can be reconstructed from known fingerprint representations, such as Minutiae Cylinder Codes, with high accuracy, which can be used to create spoof fingers and compromise biometric systems. The dissertation categorizes techniques for safeguarding biometric templates into two main groups: biometric cryptosystems and template transformation techniques. Biometric cryptosystems bind secure keys to biometric data to create secure sketches that cannot be used to recover the original data or the key. Template transformation techniques non-invertibly transform biometric templates using the user's password. The research analyzes and improves these techniques, focusing on fuzzy vault and fuzzy commitment, which are used to secure templates represented as points or binary vectors, respectively. An improved security analysis is provided, considering the non-uniform distribution of biometric features. The dissertation also proposes a framework to effectively combine multiple biometric representations and evaluates various template transformation techniques using comprehensive metrics. The analysis of template inversion, or the recovery of the original template from a transformed one, is a key element of security analysis. The research develops techniques for template inversion and evaluates the security of two different transformed templates: one based on point set representation and the other on binary vector representation. The analysis indicates that while these techniques are generally considered secure, they are vulnerable to inversion attacks. The protection of biometric templates is crucial for public acceptance, as the potential compromise of system security and user privacy is significant. The dissertation emphasizes the importance of rigorous analysis of the security provided by techniques used to protect biometric templates. It concludes that the security analysis presented will help streamline the development of new techniques and lead to a robust solution for protecting biometric data. The research also acknowledges the contributions of various individuals and institutions that supported the work, including advisors, committee members, and colleagues.