Methods, apparatuses and articles for testing security of a mapping function—such as a Physically Unclonable Function (PUF)—of an integrated circuit (IC) are disclosed. In various embodiments, one or more tests may be performed. In various embodiments, the tests may include a predictability test, a collision test, a sensitivity test, a reverse-engineering test and an emulation test. In various embodiments, a test may determine a metric to indicate a level of security or vulnerability. In various embodiments, a test may include characterizing one or more delay elements and/or path segments of the mapping function. Other embodiments may be described and claimed.