Resumen de Sistemas no lineales de cifrado y autenticación de imágenes basados en el correlador óptico de transformadas conjuntas (jtc)
Opticalinformation processing systems have shown great potential for security applications. Optical encryption and authentication techniques use the parallel processing capabilities, high computing speed and also, the wide range of controllable physical parameters provided by the optical processing systems. All these features permit to obtain highly secure systems. The research here contained focuses on the design and development of opto-digital security systems based on the architecture of the joint transform correlator (JTC). The security systems presented in this thesis correspond to encryption and authentication systems. The proposed encryption systems are simple and nonlinear opto-digital systems with a twofold purpose: first, an improved quality of decrypted images in comparison with other encryption systems of similar technology, and second, a high degree of security due to the use of several keys and an improved resistance against various security attacks. All these features are achieved for all the designed encryption systems based on a JTC in the Fourier, Fresnel and fractional Fourier optical processing domains, respectively. In this work, an experimental validation of the most basic aspects of the proposed encryption system is also included. Finally, we present the integration of the photon-counting technique with the nonlinear encryption system based on a JTC in order to authenticate and verify a primary image (for instance, an image of a fingerprint) and a random phase code, respectively, in a secure and simultaneous manner. The integration of the photon-counting technique in the information processing system increases the security of the encryption system and also, makes the authentication system more robust against unauthorized attacks.
