Security-enhanced interference-based optical image encryption

Wenqi He, Xiang Peng, Xiangfeng Meng +1 more

Y. Xiong, A. He, Chenggen Quan

Mingguang Shan, Jianchao Guo, Zhi Zhong +3 more

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.

秦怡 Qin Yi, 张帅 Zhang Shuai, 巩琼 Gong Qiong +2 more

Wang Yong, Chenggen Quan

Abstract Interference-based optical encryption schemes have an inherent silhouette problem, due to the equipollent nature of the phase-only masks generated from an analytical method. We propose a new interference-based optical image encryption with silhouette removal by amplitude modulation. Different from the previous methods, which require time-consuming iterative computation or post-processing of the phase-only masks for silhouette removal, the proposed method can resolve the problem by adding an amplitude modulating operation on the original image. The introduction of the amplitude modulator can significantly enhance the security of the system, and the silhouette problem inherent in a conventional interference-based encryption method is fully resolved. The design and parameter choice of the amplitude modulator is discussed. Numerical simulations are presented to verify the validity of the proposed method.

侯俊峰 Hou Junfeng, 黄素娟 HUANG Su-juan, Guohai Situ