A Multi-User Encryption and Authentication System Based on Joint Transform Correlation

Abstract

Optical image encryption technology based on joint transform correlation (JTC) has attracted increasing attention from researchers. We propose a multi-user secure communication system based on the special properties of JTC. Multiple users utilize their own fingerprints to encrypt the plain-text in the encryption process, and each user must be first authenticated at the beginning of the decryption process. Only users with legitimate identities can perform the decryption process, whereas unauthorized users with false identities cannot, so the security of the system is greatly improved. Furthermore, we propose a multi-user double-image encryption method, which can better meet the needs of different security environments. Considering the possibility of overlapping images at the output end, we prove that a JTC-based image encryption system can avoid overlapping images at the output when the distance between the input images is 3W (W is the side length of a square image), which provides a theoretical foundation for further research. Finally, a numerical simulation demonstrates the effectiveness and feasibility of the proposed idea.Entropy 2019, 21, 850 2 of 17 Vilardy et al. analyzed JTC encryption methods and found that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum [13][14][15]. Moreover, the JTC system has been applied to different transformation domains, such as the fractional Fourier transform domain [16], Fresnel transform domain [17], and chaotic maps [18,19], which greatly expanded the application of JTC. As is known, cryptography and cryptanalysis are complementary to each other. Therefore, attack schemes against JTC encryption system are proposed [20][21][22][23][24][25][26]. At the same time, the researchers introduced authentication to improve the security of the system [27][28][29][30].In the JTC encryption system, the common feature is that the classified information is controlled by one user. However, in some cases, this information cannot be owned by one user alone. The classified information can be obtained only if two or more users are present simultaneously. In the current study, a multi-user encryption system is proposed based on JTC. The proposed cryptosystem is uniquely useful in practical applications such as co-signing important documents, the control of nuclear buttons, access to certain crucial information, and so on.The remainder of this paper is organized as follows. Section 2 proves the feasibility of the proposed scheme through mathematical theory and the analysis of potential risks. Multi-user double image encryption is proposed, and the position distribution of the output image is analyzed in Section 3. Simulation results are shown in Section 4. Finally, the conclusions are presented in Section 5. The Proposed CryptosystemOn he basis of JTC, the current report proposes a multi-user encryption system with fingerprint keys. Different system users utilize ...

Optical Correlators for Cryptosystems and Image Recognition: A Review

“…An alternative to the JTC cryptosystem is the JFTC (joint Fresnel transform correlator) one, that retains the properties of the JTC cryptosystem with additional benefits, such as the possibility of using more encryption keys, based on the position of the key mask in the input plane of the FTL and the diffraction distance [ 30 ]. Another extension of the JTC cryptosystem is in the Fresnel domain, by using phase-shifting interferometry, enabling the processes of binary data encryption and decryption to take place at a high speed and the operation in a simple and robust setup [ 34 ]. The JTC cryptosystem was also extended to the fractional Fourier and Gyrator domains, respectively, having as a result an improved quality of the images and an increased security against attacks [ 35 ].…”

“…JTC correlators have been also used for encryption and authentication systems with multiple users. In a recent implementation [ 34 ], such a system was proposed, where during the process of encryption the plain-text is encrypted by means of the fingerprints of several users, whereas at the onset of the process of decryption the authentication of each user is performed, thus eliminating the access of unauthorized ones and increasing the system security. The paper also demonstrates that the JTC is successful in avoiding the overlap between images at the output of a system with two encrypted images and multiple users, if the input images are separated by three times the side length of a square image.…”

“…The paper also demonstrates that the JTC is successful in avoiding the overlap between images at the output of a system with two encrypted images and multiple users, if the input images are separated by three times the side length of a square image. The feasibility and efficiency of the system were demonstrated by simulation results [ 34 ]. Another setup that enables the authentication of two users was proposed by another group of researchers using a nonlinear JTC [ 35 ].…”

“…Below I present the main challenges, open issues, and proposals of future enhancement for representative setups, techniques and architectures of optical correlators reviewed in this paper. The system proposed in [ 34 ], based on the JTC, for encryption and authentication of multiple users, applied on gray images, can be further extended to color images, that include more information. Moreover, it is also necessary to study the correlation results not only for images symmetrically positioned, as performed, but also when the images are randomly placed.…”

A Virtual Optical Holographic Encryption System Using Expanded Diffie-Hellman Algorithm

“…However, a long size encryption key will create another problem which will reduce the speed of the encryption process. The optical encryption technology based on holographic has emerge as a new technology that has many has many advantages such as high speed, high capacity and is multi-dimensional as well [1][2][3]. For these reasons, the optical holographic encryption technology is gradually received great attention and considered as an enabling technology [4,5].…”