VoteBox Nano: A smaller, stronger FPGA-based voting machine
Wallach, Dan S.
Master of Science
This thesis describes a minimal implementation of a cryptographically secure direct recording electronic (DRE) voting system, built with a low-cost Xilinx FPGA board. Our system, called VoteBox Nano, follows the same design principles as the VoteBox, a full-featured electronic voting system. The votes are encrypted using El-gamal homomorphic encryption and the correctness of the system can be challenged by real voters during an ongoing election. In order to fit within the limits of a minimal FPGA, VoteBox Nano eliminates VoteBox's sophisticated network replication mechanism and full-color bitmap graphics system. In return, VoteBox Nano runs without any operating or language runtime system and interacts with the voter using simple character graphics, radically shrinking the implementation complexity. VoteBox Nano also integrates a true random number generator (TRNG), providing improved security. In order to deter hardware tampering, we used FPGA's native JTAG interface coupled with TRNG. At boot-time, the proper FPGA configuration displays a random number on the built-in display. Any interaction with the JTAG interface will change this random number, allowing the poll workers to detect election-day tampering, simply by observing whether the number has changed.
Electronics; Electrical engineering; Computer science