Design and implementation of a ring oscillator-based physically unclonable function on field programmable gate array to enhance electronic security

Physically unclonable functions (PUFs) are functions that generate a set of random responses when stimulated by a set of pre-defined challenges. They are mostly used for hardware verification and/or device authentication mechanisms, access control, protection of sensitive intellectual property (IP) on devices and protection against insecure hardware connections and communications. In FPGA devices, PUFs are instantiated by exploiting the propagation delay differences of signals caused by manufacturing process variations. In this work, we describe a real implementation of ring oscillator-based PUF on Xilinx FPGAs and illustrate how such architecture is mapped into the FPGA fabric. Using this architecture, we obtained a unique 45-bit code which can be used to identify a chip between many similar devices of the same family in order to provide a reliable access control and authentication mechanism.