中文摘要：

提出了一种新的加密图像中的可逆信息隐藏算法.发送方对图像进行下采样并计算残差,得到子图像和残差两部分数据,再使用加密密钥对两部分数据分别进行加密后发送给服务器端.服务器端对残差部分的加密数据进行算术编码,产生冗余空间并使用嵌入密钥隐藏额外数据.接收端根据持有密钥的情况,从服务器端获取不同的数据版本.与以往方法相比,所提出的按需传输数据的新机制可有效减少服务器传送的数据量,且在图像可无损恢复的前提下大大提高了数据嵌入率.

英文摘要：

This paper proposes a new method of reversible data hiding in encrypted images. The sender down-samples the original image and calculates the residuals to generate two sets of objects： sub-images and residuals. These are encrypted with an encryption key and sent to the server. The server applies arithmetic coding on the encrypted residuals to generate spatial redundancy, and then hides extra data using the embedding key. With the key, the receiver obtains different versions of the data transmitted by the server. Unlike the conventional methods, a transmission-on-demand mechanism is used, which can effectively reduce the amount of transmitted data on the server. With the image perfectly recovered,the data embedding rate is greatly improved.