US Patent 11379125 Trusted field programmable gate array

An approach to creating a tamper-resistant field programmable gate array (FPGA) and remotely reprogramming the tamper-resistant FPGA. In one aspect, determining if an encryption key is stored in a physical unclonable function (PUF) of the FPGA. Further, responsive to the encryption key not being stored in a PUF, writing an encryption key in tamper resistant memory associated with a back end of the line (BEOL) of the FPGA. In another aspect, writing a program key and a look-up table (LUT) in the tamper resistant memory.