一种基于栅格结构的彩色可视密码方案

A Color Visual Cryptography Scheme Based on Grid Structure

传统的可视密码方案只能实现一张秘密图像的加密与恢复,且在像素上存在着扩展,这增加了分享图像存储与传输的数据量。该文提出一种基于栅格结构的彩色可视密码方案,可以实现对于多个秘密图像加密。基于随机栅格当中采取异或算法将彩色秘密图像的每个通道进行加密,通过拼接操作和每个通道图像的合成生成分享图像,根据不同秘密级别对不同数量分享图像进行叠加后显示原始秘密图像进而实现多个彩色秘密图像的加解密过程。该方案可实现多张在不同权限级别下彩色秘密图像加解密,且恢复的彩色图像效果良好。彩色秘密图像的加解密提升了可视密码的应用场景,基于栅格的存取结构使加密后的图像像素扩展为零,降低了加解密成本,方便对于图像进行存储。

The traditional visual cryptography scheme can only achieve the encryption and recovery of a secret image, and there is an extension on the pixel, which increases the amount of data stored and transmitted by the shared image. This paper proposes a color visual cryptography scheme based on grid structure, which can realize encryption of multiple secret images. An exclusive algorithm is used to encrypt each channel of the color secret image based on the random grid, and the shared image is generated by the splicing operation and the synthesis of each channel image, and the original number of the shared image is superimposed according to different secret levels to display the original secret image and finally an encryption and decryption process of a plurality of color secret images is implemented. The scheme can realize multiple color secret image encryption and decryption under different permission levels, and the restored color image works well. The encryption and decryption of the color secret image enhances the application scenarios of the visual password. The grid-based access structure expands the encrypted image pixels to zero, which reduces the cost of encryption and decryption and facilitates storage of the image.