Multiple-image Authentication Research Articles

Multiple-image authentication method based on phase-only holograms and a logistic map

An interesting security method for a multiple-image authentication scheme is proposed based on computer-generated holograms and a logistic map. First, each original image is encoded as the complex-valued hologram under the point light source model. The resulting hologram is then converted to a phase-only hologram using the Floyd-Steinberg dithering algorithm. Second, each phase-only hologram is randomly sampled with the aid of a binary mask. Through the catenation of all selected pixels, a phase-only pixel sequence is formed. Finally, a non-periodic and non-converging sequence generated with the logistic map is used to scramble this sequence. After only preserving the phase data of the scrambled sequence, the real-valued ciphertext carrying the information of all original images is obtained. In the process of authentication, although no valid information can be discerned from noisy reconstructed images at a small sampling rate, the verification of original images can be efficiently accomplished using the nonlinear correlation maps. Besides binary masks, the parameters of the logistic map are served as secret keys. Due to their high sensitivity, the security of the proposed method is greatly enhanced. The proposed authentication mechanism has been demonstrated to be effective and robust through experiments. To our knowledge, it is the first time to implement multiple-image authentication using phase-only holograms, which can provide a new perspective for optical information security.

Multiple-image authentication based on metasurface and phase retrieval with sparsity constraints

In this paper, a multiple-image authentication method is proposed based on metasurface and phase retrieval with sparsity constraints. In the encryption process, multiple plaintext images are firstly encrypted to a phase-only hologram by using phase retrieval algorithm with sparsity constraints and iterative Fourier transform algorithm, and then the phase-only hologram is converted into a metasurface hologram for multiple-image authentication with the help of a geometric-phase metasurface unit, greatly expanding the encoding information capacity of metasurface for authentication. In the authentication process, the reconstructed image of metasurface hologram is respectively authenticated with multiple plaintext images through nonlinear correlation authentication such that multiple identities of the user holding this metasurface can be simultaneously verified, overcoming the problem that the metasurface for authentication and user identity can only be one-to-one, and substantially improving the efficiency of identity authentication. In order to demonstrate the feasibility of the proposed multiple-image authentication method, a series of numerical simulations are performed, and the simulation results show that the proposed method exhibits high feasibility and security as well as authentication efficiency, and the metasurface for multiple-image authentication has strong robustness against cropping attack.

Optical multiple-image authentication method based on Fourier single-pixel imaging and multiple logistic maps.

As a promising technique, the spatial information of an object can be acquired by employing active illumination of sinusoidal patterns in the Fourier single-pixel imaging. However, the major challenge in this field is that a large number of illumination patterns should be generated to record measurements in order to avoid the loss of object details. In this paper, an optical multiple-image authentication method is proposed based on sparse sampling and multiple logistic maps. To improve the measurement efficiency, object images to be authenticated are randomly sampled based on the spatial frequency distribution with smaller size, and the Fourier sinusoid patterns generated for each frequency are converted into binarized illumination patterns using the Floyd-Steinberg error diffusion dithering algorithm. In the generation process of the ciphertext, two chaotic sequences are used to randomly select spatial frequency for each object image and scramble all measurements, respectively. Considering initial values and bifurcation parameters of logistic maps as secret keys, the security of the cryptosystem can be greatly enhanced. For the first time to our knowledge, how to authenticate the reconstructed object image is implemented using a significantly low number of measurements (i.e., at a very low sampling ratio less than 5% of Nyquist limit) in the Fourier single-pixel imaging. The experimental results as well as simulations illustrate the feasibility of the proposed multiple-image authentication mechanism, which can provide an effective alternative for the related research.

An optical multiple-image authentication based on computational ghost imaging and total-variation minimization

An optical multiple-image authentication is suggested using computational ghost imaging and total-variation minimization. Differing from encrypting multiple images into a noise-like ciphertext directly, as described in most conventional authentication methods, the related encoded information is embedded into a cover image to avoid the attention of eavesdroppers. First, multiple images are encoded to form real-valued sequences composed of corresponding bucket values obtained by the aid of computational ghost imaging, and four sub-images are obtained by decomposing the cover image using wavelet transform. Second, measured sequences are embedded into one of the sub-images, and embedding positions are randomly selected using corresponding binary masks. To enhance the security level, a chaotic sequence is produced using logistic map and used to scramble measured intensities. Most importantly, original images with high quality can be directly recovered using total-variation minimization. The validity and robustness of the proposed approach are verified with optical experiments.

Optical multiple-image authentication based on computational ghost imaging and hybrid non-convex second-order total variation.

An optical security method for multiple-image authentication is proposed based on computational ghost imaging and hybrid non-convex second-order total variation. Firstly, each original image to be authenticated is encoded to the sparse information using computational ghost imaging, where illumination patterns are generated based on Hadamard matrix. In the same time, the cover image is divided into four sub-images with wavelet transform. Secondly, one of sub-images with low-frequency coefficients is decomposed using singular value decomposition (SVD), and all sparse data are embedded into the diagonal matrix with the help of binary masks. To enhance the security, the generalized Arnold transform is used to scramble the modified diagonal matrix. After using SVD again, the marked cover image carrying the information of multiple original images is obtained using the inverse wavelet transform. In the authentication process, the quality of each reconstructed image can be greatly improved based on hybrid non-convex second-order total variation. Even at a very low sampling ratio (i.e., 6%), the existence of original images can be efficiently verified using the nonlinear correlation maps. To our knowledge, it is first to embed sparse data into the high-frequency sub-image using two cascaded SVDs, which can guarantee high robustness against the Gaussian filter and sharpen filter. The optical experiments demonstrate the feasibility of the proposed mechanism, which can provide an effective alternative for the multiple-image authentication.

Improved multiple-image authentication based on optical interference by wavelength multiplexing.

In this paper, an improved multiple-image authentication based on optical interference by wavelength multiplexing is proposed, which has high security and easy optical implementation. The Fresnel spectra of original images are diffracted from the same axial position but by different wavelengths, which makes the optical implementation easy and stable without any mechanical translation. Then, the Fresnel spectra are sparsely sampled by predesigned binary amplitude masks and diffracted again, and all spectra are multiplexed into one synthetized spectrum. Finally, the synthetized spectrum is analytically decomposed into one phase-only mask and one amplitude-only mask by an improved interference-based encryption (IBE) scheme. Benefiting from the wavelength multiplexing, the encryption capacity is enlarged, and the optical implementation for decryption becomes easy. With the aid of the sparse sampling, every decrypted image could be entirely unrecognizable but authenticated by nonlinear correlation. Moreover, instead of a conventional IBE, an improved IBE is used in this scheme, which can attenuate the information leakage and further enhance the security. Various numerical simulation results are presented to demonstrate the feasibility and effectiveness of this scheme.

Interference-based multiple-image encryption and authentication via lateral shift multiplexing and sparsification

We report a novel optical method of interference-based multiple-image encryption and authentication via lateral shift multiplexing and sparsification. We encode multiple original images into two ciphertexts only containing partial information of the multiple images when the secret key generated randomly is laterally movable within a predefined interval, and we analytically derive the two other keys of each original image. Information discrimination for each original image as well as its silhouette is still prohibited in spite of the utilization of one, two, three, or even four masks for decryption. The three secret keys of each original image significantly improve the security of the proposed method, and binary amplitude masks are included in the decryption and authentication procedure. Moreover, the proposed scheme completely eliminates the cross-talk problem and destroys any high correlation between the plaintexts and ciphertexts. Numerical simulations are executed to prove the effectiveness and security of this scheme.

Optical multiple-image authentication and encryption based on phase retrieval and interference with sparsity constraints

An optical multiple-image authentication and encryption method based on phase retrieval algorithm (PRA) in the Fresnel domain and interference with sparsity constraints is proposed. In our proposed method, sparse phase and space multiplexing technique are respectively introduced to authentication and encryption for multiple-image. Each target image is respectively encrypted into two phase-only masks, which contain the phase data generated from three binary images by applying PRA in the Fresnel domain and need to be verified before used for decryption. That the target images are respectively reconstructed by using different decryption keys in the proposed method increases the security of the cryptosystem. Numerical simulation shows that the proposed method has high multiplexing capacity and security.

Multiple-image authentication based on the single-pixel correlated imaging and multiple-level wavelet transform

Single-pixel correlated imaging has been developed as one of the most promising techniques in the past decades. In this paper, a new mechanism of single-pixel correlated imaging is designed for multiple-image authentication. The object wave is sequentially modulated by a series of phase-only mask pairs embedded into two cascaded spatial light modulators. The modulated wave passes through the input image located in the object plane, and its intensity is recorded as one of the ciphertext values by using a single-pixel bucket detector without spatial resolution. The sparse data of plaintext images are obtained with the multiple-level wavelet transform and used to construct an interim image with the help of binary amplitude masks. The interim image with a smaller size than that of plaintext images is considered as the input of single-pixel correlated imaging, which can guarantee the number of measurements reduced. Simultaneously, the phase-only mask pairs are retrieved from the 2D patterns formed with the row vectors of the spatially orthogonal Hadamard matrix by using an efficient iterative phase retrieval algorithm. Because the redundancy between speckle patterns generated with these phase-only mask pairs is greatly restrained, the number of measurements can be further reduced. Moreover, the related binary amplitude masks are employed as the secret keys so that the security level is also extensively enhanced. Given the above, the proposed method can significantly achieve the goal of multiple-image verification and provide a different research approach for optical authentication based on single-pixel correlated imaging.

An optical multiple-image authentication based on transport of intensity equation

An optical multiple-image authentication approach based on transport of intensity equation technique has been proposed. Initially, a phase-encoded plaintext is synthesized with significant blocks chosen from the multiple plain images by evaluating their spatial frequency coefficients, which is bonded with a random intensity mask generated with logistic map to constitute the complex amplitude. Then, the complex amplitude is encrypted to a real-valued ciphertext with noise-like distribution by using Fresnel diffraction. In the process of authentication, the phase information is firstly reconstructed by solving transport of intensity equation. The existence of a plain image can be identified by calculating the nonlinear correlation between it and its partial data only containing the extracted significant blocks from the phase information by aid of the corresponding binary mask. To our best knowledge, it is the first time to apply the transport of intensity equation technique to implement the optical multiple-image authentication. A set of numerical simulations are carried out to demonstrate the feasibility of the proposed approach.

Optical multiple-image authentication scheme based on the phase retrieval algorithm in gyrator domain

A novel optical multiple-image authentication scheme based on the phase retrieval algorithm is presented in gyrator domain. According to a plain image, only one phase-only mask is obtained as the encrypted result by using the proposed phase retrieval algorithm, which has a fast convergence rate and good performance on mean square error. Afterwards, the sparsely encrypted distribution is extracted from the phase-only mask by selecting a certain percentage of pixels randomly. Different from other multiple-image authentication system based on space multiplexing, all sparsely encrypted distributions of plain images are finally integrated into the ciphertext by making use of the inter-modulation operation of phase masks, where the decryption process can be performed efficiently without any cross-talk noise and the encrypted capacity is nearly unlimited. Only when the secret keys are correct, the content of the plain images can be authenticated, in which the authentication process can be implemented optically by using the architecture of double random phase encoding. Simulation results are given to demonstrate the feasibility and robustness of the proposed scheme.

Security enhanced multiple-image authentication based on cascaded optical interference and sparse phase mixed encoding

An interference-based cascaded filtering method is proposed to perform multiple-image authentication. By using spatial phase mixed encoding technique and phase retrieval iteration in Fresnel transform domain, multiple original images are encoded in two phase-only cipher texts. Using correct keys in an interference-based configuration, one can only recover a noisy image without any secret information revealed. A cascaded phase-only filtering structure, instead of correlation methods, is applied to perform authentication where the decrypted image is converted into a pre-specified irregular pattern that functions as authentication criterion. The proposed structure can strengthen security greatly because authentication output strongly depends on the decrypted images and authentication keys. Moreover, the decryption and authentication procedures can be completed optically in a more compact way than previous methods. Simulation results have been given to prove the effectiveness of this proposal and evaluate its performance.

Multiple-image authentication with a cascaded multilevel architecture based on amplitude field random sampling and phase information multiplexing.

A multiple-image authentication method with a cascaded multilevel architecture in the Fresnel domain is proposed, in which a synthetic encoded complex amplitude is first fabricated, and its real amplitude component is generated by iterative amplitude encoding, random sampling, and space multiplexing for the low-level certification images, while the phase component of the synthetic encoded complex amplitude is constructed by iterative phase information encoding and multiplexing for the high-level certification images. Then the synthetic encoded complex amplitude is iteratively encoded into two phase-type ciphertexts located in two different transform planes. During high-level authentication, when the two phase-type ciphertexts and the high-level decryption key are presented to the system and then the Fresnel transform is carried out, a meaningful image with good quality and a high correlation coefficient with the original certification image can be recovered in the output plane. Similar to the procedure of high-level authentication, in the case of low-level authentication with the aid of a low-level decryption key, no significant or meaningful information is retrieved, but it can result in a remarkable peak output in the nonlinear correlation coefficient of the output image and the corresponding original certification image. Therefore, the method realizes different levels of accessibility to the original certification image for different authority levels with the same cascaded multilevel architecture.

Asymetric multiple-image authentication based on complex amplitude information multiplexing and RSA algorithm

By combining the iterative phase retrieval algorithm in the Fresnel domain with the shift rotation permutation operations of row vectors and column vectors, a new kind of asymmetric multiple-image authentication based on complex amplitude information multiplexing and RSA algorithm is proposed, where multiple complex amplitude information in the input plane is retrieved and generated by the phase retrieval algorithm in the Fresnel domain. In original binary amplitude mask, the row vector and column vectors random numbers are randomly generated in advance, such that each sampling mask for each authenticator is obtained by the shift rotation permutation operations of corresponding row vector and column vectors random numbers for original binary amplitude mask. Thus, one synthesized complex amplitude is generated by the operations of sampling, overlap and multiplexing, and then sent to the certification center for authentication use. At the same time, the row vector and column vectors random numbers are encoded to ciphers by the public keys of RSA algorithm, and then delivered to the corresponding authenticators. During the authentication process, the row vector and column vectors random numbers are first decoded by the private keys possessed by the authenticator; second, the authenticator’s sampling mask is reconstructed by the shift rotation permutation operations of the above decoded random numbers for original binary amplitude mask. Finally, the authenticator with other additional authentication keys is prompted to place the synthesized complex amplitude information and its sampling mask at the corresponding positions, when the system is illuminated by a plane wave with the correct wavelength. A recovered image is then recorded in the output plane, by calculating and displaying the nonlinear correlation coefficient between the recovered image and the certification image, if there exists a remarkable peak in its nonlinear correlation coefficient distributions, indicating that the authentication is successful. On the contrary, if there is no remarkable peak but uniformly distributed white noise in the map, the authentication process is a failure attempt. Any intruder with randomly generated forged authentication keys will end up with a failure which enhances the security of the system to some extent.

Optical multiple-image authentication based on modified Gerchberg–Saxton algorithm with random sampling

It is well known that cross-talk terms can highly affect quality of recovered images in optical cryptography systems, such as multiple-image encoding. In this paper, we propose optical multiple-image authentication based on modified Gerchberg–Saxton algorithm with random sampling. We demonstrate that influence of cross-talk term is not highly significant, and to some extent it can be useful for the proposed optical multiple-image authentication system. In addition, system capacity can be arbitrarily controlled by the use of random sampling, and high capacity and high flexibility can be guaranteed.