PROCESSING DEVICE, NON-TRANSITORY STORAGE MEDIUM, AND SYSTEM

There is provided a processing device to which different unique constants are allocated among devices of the same type, the processing device comprising: a processing unit that performs a calculation based on a common code that is issued by a code issuing device and is used in common by the plurality of processing devices, and the specific constant allocated to the processing device, and executes a subsequent process using a result of the calculation, wherein, prior to the subsequent process, the processing unit executes a determination of whether or not each of a result of a calculation based on the specific constant allocated to the processing device and a result of a calculation based on the specific constant allocated to at least one other processing device is a valid value.