The ability of metamaterials to manipulate optical waves in the spatial and spectral domain has provided opportunities for image encoding. This combined with recent advances in hyperspectral imaging suggest exciting new opportunities for secure encryption. In this work, we propose a multi-channel scheme for secure image transmission across multiple wavelength channels. In contrast to conventional encryption schemes that perform a 1-to-1 transformation on a given plain image, we propose a 1-to-n transformation. We show that our scheme provides security against attacks of varying complexity provided a reasonable number of spectral channels is used.
The ability of metamaterials to manipulate optical waves in the spatial and spectral domain has provided opportunities for image encoding. This combined with recent advances in hyperspectral imaging suggest exciting new opportunities for secure encryption. In this work, we propose a multi-channel scheme for secure image transmission across multiple wavelength channels. In contrast to conventional encryption schemes that perform a 1-to-1 transformation on a given plain image, we propose a 1-to-n transformation. We show that our scheme provides security against attacks of varying complexity provided a reasonable number of spectral channels is used.
The secure transmission of image information is an essential issue in communication, but it is also important in situations where the transmission channel resources are limited, such as quantum transmission. We propose a multi-layer single-pixel imaging end-to-end optical encryption framework with the characteristic advantage of a small key storage space requirement. Compared with previous single-layer encryption methods, the proposed approach greatly expands the key space and enhances the difficulty of brute-force cracking. The framework encrypts the image when the imaging signal is measured, which avoids the risk of leaking the plaintext information in processing. Numerical simulations and experiments verify the feasibility and robustness of this method. The proposed method can encrypt images end-to-end in both spatial and frequency domains, offering a new framework for robust, affordable, and secure optical image encryption.
Multi-channel information encryption technology has been implemented by metasurfaces owing to their superior capability in manipulating phase, amplitude, wavelength and polarization of incident light. However, any non-full-channel decoding may lead to the leakage of secret information. To further improve the security of information, in this paper, we propose a channel shared information encoding scheme by integrating visual secret sharing scheme with metasurface-based phase-encoding technique. The secret information can be reconstructed only by decoding all the wavelength channels of the metasurface, whiles meaningless images would be extracted in other channel decoding processes, without revealing any original information. The simulated results show the feasibility and adjustability of our encryption system, which can be potentially applied in future optical information security systems.
Information security has attracted much current attention due to the rapid development of modern technologies, such as computer and internet. We propose a novel method for optical image encryption using multilevel Arnold transform and rotatable-phase-mask noninterferometric imaging. An optical image encryption scheme is developed in the gyrator transform domain, and one phase-only mask (i.e., phase grating) is rotated and updated during image encryption. For the decryption, an iterative retrieval algorithm is proposed to extract high-quality plaintexts. Conventional encoding methods (such as digital holography) have been proven vulnerably to the attacks, and the proposed optical encoding scheme can effectively eliminate security deficiency and significantly enhance cryptosystem security. The proposed strategy based on the rotatable phase-only mask can provide a new alternative for data/image encryption in the noninterferometric imaging.
The rise of quantum computing poses an imminent threat to traditional cryptographic algorithms such as Advanced Encryption Standard (AES) and Rivest, Shamir, Adleman (RSA), necessitating innovative solutions to ensure data security in the post-quantum era. This paper introduces a novel multi-level image encryption system that combines post-quantum and conventional techniques to address this challenge. By leveraging the Quantum Fourier Transform (QFT) to decompose images, encrypting low-frequency components with Advanced Encryption Standard (AES), and securing AES keys with the quantum-resistant Learning with Errors (LWE) method, this approach offers robust protection against classical and quantum attacks. Empirical evaluations using metrics such as Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), entropy, and correlation coefficients demonstrate the system's ability to maintain image quality while delivering exceptional security. Scalable and effective, this framework is well-suited for safeguarding critical applications in fields such as medicine, defense, and finance.
Abstract Information security and authentication are important challenges facing society. Recent attacks by hackers on the databases of large commercial and financial companies have demonstrated that more research and development of advanced approaches are necessary to deny unauthorized access to critical data. Free space optical technology has been investigated by many researchers in information security, encryption, and authentication. The main motivation for using optics and photonics for information security is that optical waveforms possess many complex degrees of freedom such as amplitude, phase, polarization, large bandwidth, nonlinear transformations, quantum properties of photons, and multiplexing that can be combined in many ways to make information encryption more secure and more difficult to attack. This roadmap article presents an overview of the potential, recent advances, and challenges of optical security and encryption using free space optics. The roadmap on optical security is comprised of six categories that together include 16 short sections written by authors who have made relevant contributions in this field. The first category of this roadmap describes novel encryption approaches, including secure optical sensing which summarizes double random phase encryption applications and flaws [Yamaguchi], the digital holographic encryption in free space optical technique which describes encryption using multidimensional digital holography [Nomura], simultaneous encryption of multiple signals [Pérez-Cabré], asymmetric methods based on information truncation [Nishchal], and dynamic encryption of video sequences [Torroba]. Asymmetric and one-way cryptosystems are analyzed by Peng. The second category is on compression for encryption. In their respective contributions, Alfalou and Stern propose similar goals involving compressed data and compressive sensing encryption. The very important area of cryptanalysis is the topic of the third category with two sections: Sheridan reviews phase retrieval algorithms to perform different attacks, whereas Situ discusses nonlinear optical encryption techniques and the development of a rigorous optical information security theory. The fourth category with two contributions reports how encryption could be implemented at the nano- or micro-scale. Naruse discusses the use of nanostructures in security applications and Carnicer proposes encoding information in a tightly focused beam. In the fifth category, encryption based on ghost imaging using single-pixel detectors is also considered. In particular, the authors [Chen, Tajahuerce] emphasize the need for more specialized hardware and image processing algorithms. Finally, in the sixth category, Mosk and Javidi analyze in their corresponding papers how quantum imaging can benefit optical encryption systems. Sources that use few photons make encryption systems much more difficult to attack, providing a secure method for authentication.