This book studies the security of Physical Unclonable Functions (PUFs) based on the Arbiter PUF design, with a focus on so-called modeling attacks. The author shows the insecurity of several designs and proposes a novel construction that is proven to be immune against attacks known in scientific literature. The book explores designs of variants and compositions of the Arbiter PUF, which was introduced as a CMOS-compatible, electrical PUF design, and has received a lot of research attention, albeit being insecure with respect to modeling attacks. After revisiting modeling attacks on the...