| 摘要 |
In an encryption storage apparatus (data storage apparatus) ( 1 ), when entered an allocation request signal (a 1 ), a key management section ( 7 ) outputs a generation request signal (b) to a random number generation section ( 3 ). The random number generation section ( 3 ) generates a pseudorandom number as an encryption key (c) at the entering timing of the generation request signal (b), and the key management section ( 7 ) causes a volatile key storage section ( 4 ) to store the encryption key (c) and returns a corresponding key number (a 2 ) to a user side. When the user enters an encryption instructing signal (a 3 ) and the key number (a 2 ) to the key management section ( 7 ), the key management section ( 7 ) reads out the corresponding encryption key (c), and an encryption section ( 5 ) converts entered data (d 1 ) into encrypted data (d 2 ) and stores the encrypted data (d 2 ) in a nonvolatile storage section ( 2 ). When the user enters decryption instructing signal (a 4 ) and the key number (a 2 ) to the key management section ( 7 ), the key management section ( 7 ) reads out the corresponding encryption key (c) and a decryption section ( 6 ) converts the encrypted data (d 2 ) to decrypted data (d 3 ). This can prevent non-interested persons from recognizing stored data in a nonvolatile storage apparatus in chain manner. |
