Reverse Engineering for Xilinx FPGA Chips using ISE Design Tools
Abstract
SRAM-based Field Programmable Gate Arrays (FPGAs) are more widely used compared to Flash-based and anti-fuse based FPGAs in various industries. One disadvantage of the SRAM-based FPGA is that SRAM is natively volatile and thus it requires additional nonvolatile memory to store the netlist information of the circuit outside the FPGA. When the FPGA is powered on, the bitstream file is transferred from the external nonvolatile memory to the SRAM-based FPGA. The secure issues arise if the bitstream is modified or corrupted by attacker resulting in a fatal problem in the circuit. Therefore, reverse engineering that converting a bitstream into an internal netlist is necessary to find such harmful modification. In this paper, we describe the overall process of reverse engineering based on ISE design tools in details. According to the experimental results, the proposed reverse engineering tool can recover 88% internal circuit as for the example of 64-bit LFSR design.