An information storage apparatus includes a storage unit configured to store an encrypted content and an encryption key to be applied to decryption of the encrypted content, the storage unit including a protected area in which a converted encryption key is stored and to which access restrictions are set, the converted encryption key being a data item acquired through conversion of the encryption key, and a general purpose area storing the encrypted content and an encrypted content signature file set correspondingly to the encrypted content, the encrypted content signature file containing, as a recorded data item, a block identifier indicating in which of areas in the protected area storage of the converted encryption key is permitted, to permit a reproducing apparatus to execute content reproduction possibility judgment applying the block identifier, the reproducing apparatus being configured to read the encrypted content from the storage unit and execute a reproducing process.