关键词: 图像加密算法, 压缩感知, 整数小波变换, 分段正交匹配追踪算法, 信息安全

Abstract: n order to achieve more reliable and secure transmission, image encryption technology has been commonly used for transmission of important image data. However, the encrypted images generated by traditional encryption algorithms are texture-like or noise-like images which can be easily distinguished by human visual system. A meaningful image encryption algorithm in ciphertext is designed and implemented. Combined the compressed sensing of images with the wavelet transform technology to encrypt image which makes the encrypted image on the vision is the same as the ordinary images, reduces the chance of being attacked. The algorithm achieves the following operations by using Matlab programming: reading the secret images, pre-encrypting the secret images, pre-processing the cover images, embedding the encrypted images in cover images; loading the encrypted images, extracting the pre-encrypted images and reconstructing the secret images. For the pre-encryption to the secret image, it mainly uses the compressed sensing of images based on discrete wavelet transform; when embedding the encrypted image on cover images or extracting it from them, the encryption and decryption based on the content of integer wavelet transform is mainly used; while reconstructing secret image, the stagewise OMP reconstruction algorithm is mainly used. Finally, the algorithm realized the meaningful ciphertext image encryption with certain robustness.

Key words: image encryption algorithm, compressive sensing, integer wavelet transform, stagewise OMP, information security