摘要 |
In this searchable cryptograph processing system in which a registered client and a management server are connected via a network, the registered client is provided with a registered client processing unit that generates, on the basis of the difference between a first secret key for encrypting plaintext data and a second secret key for newly encrypting the plaintext data, a difference key mask for updating, by using the second secret key, confidential data encrypted by the first secret key. |