Decryption processing apparatus, decryption method and image forming apparatus

摘要

There is described a decryption processing apparatus and an image forming apparatus, which make it possible to prevent the encrypted data from being incorrectly decrypted by employing a wrong decryption key. The decryption processing apparatus for decrypting encrypted digital data including encrypted code and encrypted data, includes: a first decryption section to generate decrypted diagnosis code by decrypting the encrypted code; a second decryption section to decrypt the encrypted data; a determination section to determine based on the diagnosis code whether a decryption process of the encrypted code is normally executed; and a control section to allow starting decryption process of the encrypted data by the second decryption section when the decryption process of the encrypted code is normal, and to prohibit starting the decryption process of the encrypted data by the second decryption section when the decryption process of the encrypted code is abnormal.