The role of photons in cryptanalysis

Photons can be exploited to reveal secrets of security ICs like smartcards, secure microcontrollers, and cryptographic coprocessors. One such secret is the secret key of cryptographic algorithms. This work gives an overview about current research on revealing these secret keys by exploiting the photonic side channel. Different analysis methods are presented. It is shown that the analysis of photonic emissions also helps to gain knowledge about the attacked device and thus poses a threat to modern security ICs. The presented results illustrate the differences between the photonic and other side channels, which do not provide fine-grained spatial information. It is shown that the photonic side channel has to be addressed by software engineers and during chip design.