KEY MANAGEMENT SYSTEM

摘要

A master key management device includes re-encryption key generation means for generating, by using a first secret key stored in first storage means and a third public key, a re-encryption key used to re-encrypt a second secret key which is stored in second storage means and which is encrypted with a first public key to the second secret key encrypted with the third public key. A key management server device includes reception means for receiving the generated re-encryption key from the master key management device while the master key management device and the key management server device are connected to each other, and third storage means for storing the received re-encryption key. The master key management device and the key management server device are disconnected after the re-encryption key is stored in the third storage means.