Patent ID: 8726374

Claim:
A management device for managing an information security device that includes a plurality of monitoring modules that monitor for tampering, the management device comprising: a non-transitory memory device that stores a program; and a processing device that executes the program to cause the management to device to operate as: a reception unit that receives, from the information security device, a plurality of monitoring results generated by the monitoring modules each monitoring another monitoring module; a detection unit that detects whether any normal monitoring module that has not been tampered with exists by referring to the monitoring results; a first hypothesis unit that selects, when the detection unit detects existence of a monitoring module that has not been tampered with, a monitoring module among the plurality of monitoring modules and hypothesizes that the selected monitoring module has been tampered with; a second hypothesis unit that successively applies a procedure to monitoring modules other than the selected monitoring module by referring to the monitoring results, starting from the selected monitoring module, the procedure being to hypothesize that any monitoring module determining that a monitoring module hypothesized to have been tampered with is normal has also been tampered with; and a determination unit that determines whether, as a result of the procedure by the second hypothesis unit, all of the monitoring modules are hypothesized to have been tampered with, and when determining that all of the monitoring modules are hypothesized to have been tampered with, determines the selected monitoring module to be a normal monitoring module that has not been tampered with, thereby reversing the hypothesis by the first hypothesis unit as being incorrect, wherein the detection unit detects, by referring to previously received monitoring results and currently received monitoring results, existence of the normal monitoring module when all monitoring modules are determined to be normal in the previously received monitoring results and not all modules are determined to be normal in the currently received monitoring results, and wherein a time between generation of the previously received monitoring results and generation of the currently received monitoring results is less than a predetermined threshold.