Field Programmable Gate Array (FPGA) Physical Unclonable Functions

Physical Unclonable Functions (PUFs) are a less expensive and more secure alternative to the use of non-volatile memories to provide the secret storage. A PUF is a function that maps a set of challenges to a set of responses based on an intractably complex physical system. Given a fixed challenge, the corresponding response will vary across different ICs since the variations in the manufacturing process cause significant delay differences among different ICs. However, one major problem with current hard and soft PUFs is that they possess relatively low entropy. For this proposal Secuics is introducing a new increased entropy and unbiased PUF design based on basic existing"delay-based"but biased PUF elements. We call this new design a Pattern PUF. Compared to the basic PUF designs, the Pattern PUF allows an easier implementation for both ASICs and FPGAs, provides unbiased outputs, and provides an easier evaluation and expansion of the entropy while providing higher reliability/repeatability. The Pattern PUF circuit can be used as a random number generator (RNG) and a secret volatile key generator for cryptographic operations. A multi-bit PUF signature can be generated by running the circuit multiple times or by instantiating multiple instances of the Pattern PUF.