Fig. 5: Experiments on single fingerprint chips.
From: Perfect secrecy cryptography via mixing of chaotic waves in irreversible time-varying silicon chips
a Scanning electron microscope (SEM) image of a fabricated sample. b, c Example of irreversible transformation sequence, characterized by b the deposition of water not purified with colloidal suspensions, and c same chip dried out. d Transmission spectra and generated bit sequences corresponding to four different input positions, spaced by 10 μm each. e–h Correlation entropy between the bit sequences generated from identical input positions in e the same chip, f the same chip in direct and reciprocal configuration, g the original chip and the chip modified in b, h the chip modified in b, and the chip modified in c and the original structure.
