1. A method of non-deterministic word generation from a noise source providing a bit flow, comprising: parallelizing, by a temporary storage device, the bit flow provided by the noise source to obtain first words, each first word having a first number of bits; applying, by a compression circuit, to said first words a compression function providing second words, each second word having a second number of bits, and, separately from applying to said first words a compression function, applying, by a diffusion/confusion circuit, to said first words a diffusion/confusion function providing third words, each third word having a third number of bits, the first words being input to the compression circuit and to the diffusion/confusion circuit in parallel; and selecting a second number of bits from an output of the diffusion/confusion circuit based on an output of the compression circuit, the selecting performed by a selection circuit, wherein the entropy per bit of the noise source is optimized by using the output of the compression circuit to select useful bits in the third words provided by the diffusion/confusion circuit, wherein a drift in the entropy of the noise source can be detected.