| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance the confidentiality of encrypted content. <P>SOLUTION: A content key encrypting part 100 encrypts a content key for encrypting unencrypted content by a user key inherent to a user preregistered as a content providing destination, and a content key decrypting part 160 decrypts the encrypted content key by a user input key inputted through an operation of an operating part 150. As a result, even if the encrypted content key is leaked to a third person, the third person can not decrypt the encryption of the content key so that the third person can not decrypt the content, which can enhance the confidentiality of the encrypted content unless the third person knows the user key used to encrypt the content key. <P>COPYRIGHT: (C)2009,JPO&INPIT |
