Physical unclonable functions (PUFs) are hardware security primitives that offer a lightweight security solution for constrained devices in IoT. However, many PUF circuits impose significant circuit implementation overhead. This work introduces the Cross-Feed (XFeed) PUF, an efficient PUF circuit with superior resiliency against machine learning attacks and a small circuit footprint. In the XFeed PUF, intermediate race conditions are fed to adjacent PUF elements. A systematic categorization and benchmarking of the interconnection strategies are performed to determine the most secure connection schemes. The results showed that the XFeed PUF has superior security efficiency compared to other arbiter-based PUFs.