Color image encryption method and decryption method based on quaternion orthogonal transformation

Abstract

The invention discloses an encryption method and a decryption method based on a color image quaternion representing method. Firstly, conjugate symmetric sequency-ordered quaternion Hadamard transform (CS-SQHT) is defined firstly and the defects such as color information loss and non-considered integrality of traditional CS-SCHT (Conjugate Symmetric Sequency-Ordered Complex Hadamard Transform) in color image encryption application; next, color image double-random phase encryption and decryption methods are provided based on CS-SQHT. According to the encryption method and the decryption method based on the color image quaternion representing method, the integrity and the dependency of three channels of a color image are taken into account, and excellent anti-attack robustness is achieved; as a result, the encryption method and the decryption method based on the color image quaternion representing method are obviously superior to the traditional CS-SCHT algorithm and appreciably superior to the existing algorithms based on quaternion; the encryption method and the decryption method are simple to implement, low in time complexity, and obviously superior to the existing algorithms based on quaternion in calculation efficiency.

Description

technical field

[0001] The invention belongs to the technical field of digital image encryption, and in particular relates to a color image encryption method and a corresponding decryption method based on conjugate symmetry-column rate quaternion Hadamard transformation. Background technique

[0002] With the popularization of the network and the rapid development of information processing and communication technology, multimedia information such as images, audio, and video can be quickly transmitted in various communication networks. While bringing convenience to people, information security issues have gradually aroused people's attention. Pay attention to. As images are the mainstream of information expression, the issue of image information security has naturally become the focus of attention. The rapid development of image acquisition technology and equipment makes most of the real images currently acquired in color, which provide more information and richer visual exp...

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