An information processing apparatus comprising a secure information unit that is set to the state not requiring security in the case where the data is transferred from a user memory space to a general purpose register, and that is set to the state requiring security in the case where the data is transferred from a secure memory space to the general purpose register. An encryption key in the secure memory space is prevented from being stolen by prohibiting the data transfer to the user memory space from the general purpose register with the value of the secure information unit set to the state requiring security.
