Medium handling apparatus

A banknote handling apparatus that handles a banknote, the banknote handling apparatus comprising:

• a first memory device that is tamper resistant;
• a second memory device that stores a plurality of executable instructions which are different versions of each other;
• a processor configured to execute the plurality of executable instructions;
• a substrate on which the first memory device is mounted;
• a depositing unit that takes the banknote into the banknote handling apparatus;
• a transport unit including a transport path connected to the depositing unit, the transport unit transports the banknote;
• a recognition unit located on the transport path, the recognition unit detects the banknote transported by the transport unit;
• and
• a storage unit that is connected to the transport path, the storage unit stores the banknote after detection by the recognition unit, wherein
• the storage unit is disposed in a safe,
• the safe is lockable,
• the substrate is installed in the safe such that access to the substrate requires unlocking of the safe, and
• the first memory device includes:
• a first memory area that stores pieces of verification information, used for verification of validity of the plurality of executable instructions, as a list which enables a search for particular verification information, wherein each of the pieces of the verification information comprises (1) a verification value calculated based on one of the plurality of executable instructions and (2) an identifier corresponding to the verification value;
• and
• a second memory area that stores identification information for identifying a piece of verification information of an executable version of the plurality of executable instructions from the list, the executable version being a version which is permitted to be executed among the plurality of executable instructions.