基于二维离散余弦变换的加密图像水印算法

Encryption Image Watermarking Algorithm Based on 2D Discrete Cosine Transform

将高级加密标准(Advanced Encryption Standard,AES)算法与基于二维离散余弦变换(Discrete Cosine Transform,DCT)的水印嵌入和提取算法相结合,得到基于二维离散余弦变换的加密图像水印算法。该算法先对嵌入水印进行AES加密,再在DCT域将加密后的水印嵌入载体图像。提取水印时,算法先对嵌入信息的载体图像进行DCT变换,再在DCT域完成嵌入信息提取,最后对提取的密文信息进行AES解密,得到嵌入水印。通过抗攻击能力分析,证明该算法能够同时保证嵌入信息的隐蔽性和安全性。

This paper combined Advanced Encryption Standard(AES)algorithm with watermark embedding and extraction algorithm based on two-dimensional Discrete Cosine Transform(DCT).An encrypted image watermarking algorithm based on DCT is proposed.The algorithm firstly encrypts the embedded watermark by AES,and then imparts the encrypted watermark into the carrier image in the DCT domain.When extracting the watermark,the algorithm first transforms the carrier image with embedded information by DCT,then extracts the embedded information in DCT domain,and finally decrypts the extracted ciphertext information by AES to obtain the embedded watermark.Through the analysis of anti-attack capability,it is proved that the algorithm can ensure the concealment and security of embedded information at the same time.