Protection of digital image copyright and authentication method

The present invention relates to a protection and verification method of digital image copyright. It uses discrete cosine transform technique to obtain discrete cosine value of every image to protected and use it as characteristic value, and uses the characteristic value of said image and contents of watermark image to make exclusive operation and mutual combination so as to produce a secret key. The legel user can utilize said secret key to extract the watermark image in the protected image, and after the secret key is registered on the impartial third party, a secret key with time-stamp and sign-seal can be obtained, and said secrete key can be used for proving the time order of said image. It combines the calculating method for producing secret key to calculate the secrete key of original image, and combines the calculating method for extracting watermark to extract out the watermark image from protected image according to the secrete key. 本发明是有关于一种数字影像版权的保护与验证方法，其是使用离散余弦转换技术以取得每一张欲保护影像的离散余弦值作为特征值，并以此影像的特征值和浮水印影像的内容使用互斥运算相互结合，进而产生一把秘密金钥，合法使用者可持有此秘密金钥来萃取出保护影像中的浮水印影像，且在将秘密金钥向公正第三者注册后，可产生具有时戳签章的秘密金钥，以证明此影像的拥有时间顺序。本发明是结合产生秘密金钥的演算法以计算出原始影像的秘密全钥、及浮水印萃取的演算法以根据秘密金钥自保护影像中萃取出浮水印影像。