Phys.org  November 6, 2020 Hardware-based Physical unclonable function (PUF) semiconductor chips have a unique physical code, however, the hardware structure had to be changed to increase the number of combinations of keys to enhance cryptographic characteristics. An international team of researchers (South Korea, USA – AFRL) has developed an encryption device that can greatly strengthen the cryptographic characteristics of PUFs selectively detecting circular polarization, without modify the hardware structure. They developed a phototransistor that can detect the circular polarization of light rotating in a clockwise or counterclockwise direction. As a proof‐of‐concept, the chiral phototransistor arrays are demonstrated as a physically […]