一种精确缩略图保持的图像加密方案  

An exact thumbnail-preserving image encryption scheme

作　　者：侯兴旺 赵若宇 张玉书 HOU Xing-wang;ZHAO Ruo-yu;ZHANG Yu-shu(College of Computer Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)

机构地区：[1]南京航空航天大学计算机科学与技术学院,江苏南京211106

出　　处：《计算机工程与科学》2022年第1期60-67,共8页Computer Engineering & Science

基　　金：国家自然科学基金(62072237)。

摘　　要：手机电脑平板等的普及,使得照片在日常生活中更容易获得,并且人们习惯将大量照片存储在云端。但是,在享受云存储带来的便利的同时,用户也容易受到隐私泄露的威胁。虽然学者们设计出许多图像加密方案用来防止隐私泄露,然而往往忽略了图像的可用性。最近,Tajik等人提出了一种精确缩略图保持的加密方案,能够很好地平衡图像的隐私与可用性。但是,该方案在加密过程中仅以2个像素为一组,效率较低。为此提出一种利用分割法加密图像的方案,该方案以3个像素为一组进行加密,用于保持密文图像的缩略图与明文图像的缩略图一致,并且该方案相比Tajik方案具有更高的效率。实验表明,这个方案能够使密文图像精确地保持与明文相同的缩略图,平衡了隐私和可用性。With the popularity of mobile phones,computers,and tablets,photos are more easily available in daily life,and people are used to storing a large number of photos in the cloud.While enjoy-ing the convenience brought by cloud storage,users are also threatened by privacy leaks.Although scholars have devised many image encryption schemes to prevent privacy leakage,they often ignore the usability of images.Recently,Tajik et al.proposed an ideal thumbnail preservation encryption scheme to balance image privacy and usability well,but this scheme only used two pixels as a group during the process of encryption and thus leads to the low efficiency.Therefore,an image encryption scheme using a segmentation method is proposed.This scheme uses three pixels as a group to do encryption,so as to keep the thumbnail of the ciphertext image consistent with the thumbnail of the plaintext image.The proposed scheme has higher efficiency than the Tajik's.Experiments show that this scheme can make the ciphertext image accurately maintain the same thumbnail as the plaintext image,which balances privacy and usability.

关 键 词：缩略图保持加密 可用性 隐私 图像加密 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]