| 摘要 |
A master key management device includes a re-encryption key generation means which, using a first private key and a third public key stored in a first storage means, generates a re-encryption key used to re-encrypt a second private key, which is encrypted with a first public key stored in a second storage means, into a second private key encrypted with the third public key. A key management server device includes: a receiving means which, in a state in which the master key management device and the key management server device are connected, receives from said master key management device a re-encryption key generated by the re-encryption key generation means; and a third storage means for storing the re-encryption key received by the receiving means. The connection between the master key management device and the key management server device is cut after the re-encryption key is stored in the third storage means. |
