| 摘要 |
PROBLEM TO BE SOLVED: To provide a decoding device with high security. SOLUTION: The decoder 101 is provided with an internal key storage section 105 that stores an internal key, a contents key storage section 107 that stores a contents key, a discrimination section 111 that discriminates whether or not contents in an initial state of the contents key storage section 107 differ from present contents, and an arithmetic section 103. When the arithmetic section 103 receives encrypted contents and the discrimination section 111 discriminates that the contents in the initial state of the contents key storage section 107 differ from the present contents, a 2nd decoding arithmetic section 1202 included in the arithmetic section 103 uses the present contents in the contents key storage section 107 as contents key to decode the encrypted contents and obtains 1st output data and outputs the 1st output data to the outside of the decoder. |
