1 河北大学电子信息工程学院，河北 保定 071000
2 河北农业大学理学院，河北 保定 071001
为了提高图像的加密效率和安全性，提出一种基于指纹密钥的光学双图像加密方法。首先，两幅待加密图像分别经置于输入平面和Gyrator变换域平面的两块指纹随机相位板的调制后，再经1次Gyrator变换，然后将Gyrator变换后的结果合成为一幅复振幅图像。最后，对得到的复振幅图像进行相位截断和振幅截断操作，得到加密图像和两个相位密钥。解密时，指纹、振幅截断得到的相位密钥、混沌系统的初值和控制参数、Gyrator变换参数均可作为解密过程中的密钥。在所提方法中，由于密钥与用户身份关联，加密系统的安全性得以进一步提高。此外，由于无需传输相位板密钥，密钥管理更为便捷。数值模拟结果表明，所提加密方法切实可行，具有较高的安全性和鲁棒性。
双图像加密 指纹密钥 Gyrator变换 随机相位编码 混沌映射 激光与光电子学进展
2023, 60(2): 0210015
Author Affiliations
Abstract
1 Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Laboratory of Information Photonic Technique, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China
2 e-mail: jxfang@mail.xjtu.edu.cn
Two-dimensional (2D) transition metal dichalcogenides (TMDs) attain increasing attention due to their exceptional nonlinear optical efficiencies, which hold promising potential for on-chip photonics and advanced optoelectronic applications. Planar TMDs have been proven to support orders-higher third-order nonlinear coefficients in comparison with common nonlinear materials. Interestingly, stronger light–matter interaction could be motivated when curved features are introduced to 2D TMDs. Here, a type of inorganic fullerene-like nanoparticles is chemically synthesized using hard mesoporous silica. By using the spatial self-phase modulation (SSPM) method, the nonlinear refractive index and third-order susceptibility are investigated in the visible range. It is found that and , two orders higher than the counterparts of planar structures. Our experimental findings provide a fresh thinking in designing nonlinear optical materials and endow TMDs with new potentials in photonic integration applications.
Photonics Research
2020, 8(12): 12001881
