Color image encryption and decryption method based on Hartley conversion and cross coding

• Main Authors: WANG JUN, SUN WENQING, WU QUANYING, ZHANG HAIPING, CHEN BAOHUA, FAN JUNLIU
• Format: Patent
• Language: Chinese; English
• Published: 16.04.2019
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

The invention relates to a color image encryption and decryption method based on Hartley conversion and cross coding. On an encryption side, a color image is firstly decomposed into monochrome imagesof three channels, and the image of each color channel is encoded. Three groups of pure phase functions are generated by using a uniformly distributed random function to serve as encryption keys, andthe image of a single channel is encrypted by using the Hartley conversion. Then, the ciphertext data of each channel are mixed by using a cross coding method. On a decryption side, a cross code is decoded at first, then the image is decrypted by using a decryption key, and finally an original color image is synthesized. In the encryption scheme proposed by the invention, the ciphertext contains no phase information, therefore the attack from a phase recovery algorithm can be completely immune, the encryption strength of the images is improved. By adoption of the method, in addition to encrypting the color image, multi