  Unique key generation is essential for encryption purposes between Internet
of Things (IoT) devices. To produce a unique key for this encryption, Physical
Unclonable Functions (PUFs) might be employed. Also, the Random Number
Generator (RNG) is used in many different domains; nonetheless, security is one
of the most important areas that require the best RNG. In this article, We
investigate the quality of random numbers generated by Physical Unclonable
Functions (PUFs). We have analyzed three Figures of Merit (FoMs), Uniqueness,
Randomness, and Reliability of PUFs implemented on different FPGAs. In our
experiments, we have operated the test devices at different temperatures
(20{\deg}F, 40{\deg}F, 60{\deg}F, 80{\deg}F, 120{\deg}F, 140{\deg}F). In the
PUF that we have analyzed, the key is generated in 1 second on average. We also
have analyzed and described the essential properties of random number generator
that is most vital considering things to secure our Internet of Things(IoT)
devices.
