Detecting Code Alteration by Creating a Temporary Memory Bottleneck

We develop a new technique whereby a poll worker can determine whether the software executing on electronic voting machines on election day has been altered from its factory version. Our generalized approach allows a human, using a known challenge-response pair, to detect attacks that involve modification or replacement of software on a computer based on the time it takes the computer to provide a correct response to a challenge. We exploit the large difference between main memory access times and cache memory access or CPU clock cycle times to significantly increase the time required to compute the right response when the software has been changed.