一种基于NEQR模型的高效的量子图像水印协议

An Efficient Quantum Image Watermarking Protocol Based on NEQR Model

量子水印以量子图像为载体,能够实现秘密信息的安全传输。本文基于新型增强量子图像表示模型(Novel Enhanced Quantum Representation of Digital Images,NEQR)提出了一种高容量的量子水印协议,该协议将大小为2^(n)×2^(n)的载体图像分割成2^(2n-2)个不重叠的像素块,该像素块中的像素点两两进行灰度值差值计算,依据所得差值对像素块进行分类,并对不同类别的像素块设置标志位。协议在水印嵌入前,需将2^(n-1)×2^(n-1)大小的水印图像扩大4倍,然后将扩大后的水印依据标志位的不同嵌入不同的载体图像最低有效位(Least Significant Bit,LSB)中。本文给出了协议实现的量子线路,合法的接收方将提取水印的量子线路作用于嵌入水印的载体图像即可获取水印信息。同时,本文在量子计算仿真环境下对协议进行了仿真实验,仿真结果说明协议具有良好的不可见性,嵌入容量较好。

Quantum watermarking uses quantum images as carriers to achieve secure transmission of secret information.This paper proposes a high-capacity quantum watermarking protocol based on Novel Enhanced Quantum Representation of Digital Images(NEQR)model.The protocol divides a carrier image with a size of 2^(n)×2^(n)into 2^(2n-2)non-overlapping pixel blocks.The pixel points in this pixel block are calculated by pairwise grayscale value difference,and the pixel blocks are classified based on the obtained difference.Flag bits are set for different categories of pixel blocks.Before embedding the watermark in the protocol,the watermark image of 2^(n-1)×2^(n-1)size needs to be enlarged by 4 times,and then the enlarged watermark is embedded into Least Significant Bit(LSB)of different carrier images based on the different flag bits.This paper presents a quantum circuit implemented by the protocol,where a legitimate receiver applies the quantum circuit that extracts the embedded watermark from the carrier image to obtain the watermark information.This paper conductes simulation experiments on the protocol in a quantum computing simulation environment,and the simulation results showed that the protocol has good invisibility and good embedding capacity.