An information processing unit is an unit which has an information division recording function in which a file is divided and stored. The information processing unit includes a first storage section for storing a first partial file of a file divided, a second storage section for storing a second partial file, a state detection section for checking an operating state of the information processing unit and detecting that the operating state has changed in a specific manner, and a control section for performing a lock processing in accordance with the state detected to the second partial file stored on the second storage section when the state detected by the state detection section is determined as a risky state in which unauthorized access can be performed.