Reliable and efficient PUF‐based cryptographic key generator using bit self‐tests

This Letter proposes a reliable and lightweight key generator based on a novel bit‐self‐test arbiter physically unclonable function (BST‐APUF). The BST‐APUF adds a delay detection circuit into a classical APUF to automatically test the delay deviation that produces each bit of the PUF response and generates a reliability‐flag for each response to indicate its reliability. The key generator collects robust responses and produces a secure key using a cryptographic entropy accumulator. FPGA implementation results show that the overhead and the helper data length of the authors proposed key generator are significantly lower than that of the state‐of‐the‐art schemes when generating a 128‐bit key with a bit error rate of 10 −9 .