TPE-GAN: Thumbnail Preserving Encryption Based on GAN With Key
Xiuli Chai, Yinjing Wang, Xiuhui Chen, Zhihua Gan, Yushu Zhang
Abstract
To balance the privacy and usability of images in the cloud, Tajik <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> recently designed a thumbnail preserving encryption (TPE) based on sum-preserving encryption, however, multiple iterations make it inefficient. We use CycleGan to simulate randomized unary encoding (RUE) and achieve a more efficient TPE. Thumbnail consistency loss is proposed to guarantee the visual quality of the encrypted image, and the quality of decrypted image is improved via ssim-loss. Besides, a decryption network with a key is retrained such that it can decrypt cipher images in multiple domains, and a binary string is adopted as the key instead of the decryption network parameters to facilitate sharing of images. Simulations verify the effectiveness of the proposed algorithm.