Optical image encryption based on linear canonical transform with sparse representation

المجلة: Optics communications

سنة النشر: 2023

تاريخ النشر: 2023-01-11

We propose optical image encryption and authentication in the linear canonical transform (LCT) method by using a sparse representation technique. The linearity in the LCT based double random phase encryption (DRPE) system caused the vulnerability of the system. Not only the linearity in the LCT -DRPE system causes the vulnerability of the system but also the LCT order parameter may cause this weakness. Therefore, the encrypted data of double random phase encoding based on LCT is integrated with sparse representation to overcome this weakness. Unlike the traditional DRPE method, only sparse data from the encrypted data is kept for decryption. The numerical simulation proved that the correct authentication results are satisfied despite the use of partially encrypted data. The randomly selective sparse encrypted data reinforces the security of amplitude encoding of DRPE-LCT. Thus, the proposed method added an additional layer to optical security systems. The attacks analysis is implemented in order to show the robustness of the proposed security. In addition, this method has fulfilled the transmission and storage requirements owing to the high reduction of information data.

Security augmenting of optical cryptosystem based on linear canonical transform domain using a full phase encoding technique

المجلة: Physica scripta

سنة النشر: 2023

تاريخ النشر: 2024-05-09

For the purpose of alleviating the vulnerability of double random phase encryption system in the linear canonical transform domain, a novel approach for optical security and cryptographic systems is presented. This proposed system uses a fully phase encoding technique to augment the security of encryption system in the linear canonical transform. The first step in this system involves phase encoding of the initial amplitude image to be ciphered and then modulated by the phase masks. The decryption process of image is the reversal operation of the encryption method. The effectiveness and sensitivity of our proposed cryptosystem for the encryption secret keys are verified. The resistance of our method against occlusion attacks is investigated. Moreover, the results demonstrate that the fully phase-based optical cryptosystem is more secure and robust than the amplitude-based scheme in a linear canonical domain.

Optical double-image cryptosystem based on a joint transform correlator in a linear canonical domain

المجلة: Applied optics

سنة النشر: 2024

تاريخ النشر: 2024-07-26

In this work, we present a new optical double-image encryption method based on a joint transform correlator (JTC) and the linear canonical domain for the simultaneous authentication of two images. This new extension of the encryption system overcame the vulnerability of the method based on the JTC and the conventional 4 f - optical processor in the Fourier domain. Although the simultaneous authentication process is satisfied in the Fourier domain, the data content is partially disclosed in false validation. Therefore, we introduce a quadratic phase encryption system of the linear canonical transform (LCT) domain in this method. The linear canonical transform domain adds more degrees of freedom to the security method due to the six LCT orders. In addition, the double-image encryption scheme became secure against intruder attacks, and it was difficult to recognize confiden- tial information during the negative validation process. A cryptanalysis is performed in terms of a chosen-plaintext attack (CPA) and chosen-ciphertext attack (CCA). Numerical simulations demonstrate the feasibility, security, and effectiveness of the proposed system.