| 摘要 |
PROBLEM TO BE SOLVED: To make it difficult for users to forge a watermarked picture and also to improve the reliability of a center which detects the watermarked picture. SOLUTION: A user terminal device 10 ciphers embedded information extracted from an input picture and preliminarily generated authetication information and outputs ciphered embedded information and authetication information as first transmission information and when the device receives second transmission information, the device authenticates the second information and also extracts the embedded information decoded from the second transmission information and outputs the extracted embedded information., When a detection center device 20 receives the first transmission information, the device decodes the first transmission information and outputs the information as the second transmission information. |
