A meta-level true random number generator

True random number generators (TRNGs) are extensively used in cryptography, simulations and statistics. In this work, we introduce, extend and analyse the concept of the randomised bit cell (RBC), introducing a second meta-level of randomisation, being able to simultaneously produce random numbers and detect active non-intrusive attacks. The concept is extended by using a corrector. Meta-stability is one way to generate true random numbers. By using electromagnetic radiation, a flip-flop (ff) in a meta-stable state can be manipulated to a known state. We clarify and comprehend open issues of meta-stable ffs such as power consumption and electromagnetic field strength. The experimental comparison though a software simulation with a standard TRNG yields a 17.69 times better distribution of zeros and ones while the TRNGs are under attack at the expense of a delay which is proportional to the quality of the random source.