A test program is run repeatedly (either as a loop that is programmed into the code of the test program itself, or by repeatedly running the test program manually in response to user input instructing repeated run(s) of the test program. At least some run(s) of the test program use a cipher key that was derived and saved by the test program during a previous run of the test program (rather than re-deriving the cipher key based on information provided by the operating system). In this way, if the corresponding cipher key, as stored in the system space of the operating system has become corrupted during previous run(s) of the test program, then the incompatibility between the corrupted cipher key in the system space, and the previously saved cipher key that was previously derived by the test program, will be more easily detected.