| 摘要 |
PROBLEM TO BE SOLVED: To provide an information processing unit that can discriminate whether tampering has been made with digital information which is made from certified information and that can decode the digital information into original digital information, so long as tampering has not been made with the information. SOLUTION: In the case of imbedding certified information to digital information received from an image input section 201, a hash value calculation section 202 generates the authentication information on the basis of the digital information, an encryption section 203 uses an encryption key to encrypt the authentication information, and an electronic watermark imbedding section 204 imbeds the encrypted authentication information to the digital information as an electronic watermark. |
