| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a file deleted from a removable medium from being restored by a file restoration tool and leaked when providing the file recorded in the removable medium to another person. <P>SOLUTION: A data body of the file to be recorded into the removable medium is encrypted by a common key encryption system. The encrypted data body and an encryption key of the common key encryption system used for encrypting the data body are recorded into the removable medium, in association with each other. When deleting the file, the encryption key of the common key encryption system for decrypting the encrypted data body is erased without erasing the encrypted data body recorded in the removable medium. <P>COPYRIGHT: (C)2011,JPO&INPIT |
