A True Random Number Generator circuit compatible with all chip manufacturing technologies including CMOS, using the different types of multiple entropy sources to enhance the different parameters of a single circuit which generates the random numbers, wherein the output of a preceding entropy source affects the entropy of the succeeding entropy source. The entropy sources include metastability supporting ring oscillator, chaos circuit, sampling jitter etc., and even more number of entropy sources. The chaos source controls the oscillation frequency of the ring oscillator and the ring oscillator's output is sampled using an independent clock source with jitter. The multiple cores of TRNGs provides up to hundreds of Gbps rate for random numbers and may form an essential component of next generation of secure hardware and communication systems.