Hierarchical image encryption based on cascaded iterative phase retrieval algorithm in the Fresnel domain

作者：Meng X F^*; Cai L Z; Wang Y R; Yang X L; Xu X F; Dong G Y; Shen X X; Zhang H; Cheng X C

来源：Journal of Optics A: Pure and Applied Optics , 2007, 9(11): 1070-1075.

DOI：10.1088/1464-4258/9/11/017

• image encryption
• digital image processing
• phase retrieval

A novel hierarchical image encryption system based on cascaded multiple- phase retrieval by an iterative Fresnel- transform algorithm is proposed. In this method a series of phase masks cascaded in free space is employed to retrieve different target hidden images in their corresponding hierarchical levels. It can realize different levels of accessibility to the secret data for different authority levels with the same system, and the higher level authority can get access to more hidden images. This approach can achieve fast convergence and high quality of the recovered images without any recognizable cross- talk noise or distortion, and the security level of this system is further enhanced by the use of a series of supplemental keys such as the orders of cascaded phase masks and the geometrical parameters in addition to all the iterated phase masks as principal keys. The feasibility of this method and its unique features are verified and analysed by computer simulations.

• 出版日期2007-11
• 单位山东大学