1. A random bit stream generator for generating a random bit stream, the random bit stream generator comprising: a plurality of feedback shift registers configured to store a plurality of bit values that represent an internal state of the random bit stream generator, wherein each feedback shift register comprises a register input for receiving register input data and a register output for providing register output data; a Boolean output function configured to receive the register output data provided by the register outputs of the plurality of feedback registers, to perform a first Boolean combination of the register output data, and to provide a corresponding output bit, wherein a plurality of successive output bits form the random bit stream; a feedback loop configured to perform a second Boolean combination of the output bit with at least one register feedback bit of at least one of the feedback shift registers, so that the register input data for the at least one feedback shift register is a function of the output bit; an auxiliary bit sequence producer configured to produce an auxiliary bit sequence; an auxiliary bit sequence combiner configured to logically combine the auxiliary bit sequence with the output bit; a second auxiliary bit sequence producer configured to produce a second auxiliary bit sequence; and a second auxiliary bit sequence combiner configured to logically combine the second auxiliary bit sequence with the register input data.