Maintaining the security of communication is very crucial nowadays. It is important in cryptographic security to have strong keys and is secretive. Random number generators are used to combat this problem by producing different and unique identification for each user in a network. Memristors has been studied as a potential tool in hardware security because of its energy efficiency and the nanotechnology fabrication process variations is more unique and random than the traditional complementary metal-oxide-semiconductor (CMOS) processes. This paper analyzes a memristor based ring oscillator random number generator design and how the relationship between the frequency and resistor or memristor affects the randomness of the generator and the implementations of this device in security application. It was concluded that as the resistor values increases, frequency of the signal decreases and Vout will also increased.