People recognition through biometric identifiers has a variety of applications today. This process is performed in plain text, which endangers the safety of data transmitted during the recognition process when performed in low security networks. Biometric identifiers are unique and invariant in the lifetime of an individual. Therefore, once the data associated with the biometric identifier are obtained, it cannot be safely use as a security mechanism, so is not possible to change it as a password or a personal identification number. For the cryptographic protection of biometric data, several models have been proposed, however, problems such as data alignment and the revocation of compromised templates during an attack have not been efficiently addressed in these models. A set of hybrid models have been proposed in the literature to facilitate the revocation and to introduce a contribution to remove the alignment process. For this end, several minutiae structures extraction mechanisms are involved, with the purpose of obtaining a model that uses a method for extracting information invariant to rotation and translation, resistant to nonlinear deformation and partial overlapping and one of the biometric cryptosystems to ensure the extracted set of data.

The recent implementation of biometrics solutions for user authentication in public networks has caused great concern about the safety and privacy of biometric data. Different vulnerabilities detected on automated fingerprint identification systems could reveal minutiae data if they are stored in plain text. In order to solve these security issues, several fingerprint minutiae template protection schemas have been proposed, among which there are the fuzzy vault, biohasing and cancellable or non-invertible fingerprint templates. To carry out an efficient biometric data protection process, the schema must meet three basic requirements: cryptographic security, revocability and performance; however, most of the schemas described to date fail in this task. A fingerprint minutiae template protection scheme must capture as much identifying information of the fingerprint as possible and solve the problem of template alignment before the comparison process is performed in the protected domain. A study on the cryptographic scheme of fingerprint minutiae template protection models and alignment methods was conducted in this work. Emphasis was placed on the cryptographic bases of minutiae template protection scheme and existing algorithms for aligning protected templates, highlighting the weaknesses of each one. As a result, the knowledge necessary to design an alignment-free minutiae template protection model was obtained.