The use of optical techniques for attacking integrated circuits (ICs) is increasingly being reported, particularly the nefarious extraction data from embedded SRAM. Such attacks can provide access to highly sensitive information such as encryption keys and bypass various security measures. Attackers usually exploit one of several interactions between light and semiconductors to generate logic-state images that reflect data in memory. Thermal laser stimulation (TLS) and laser probing via electro-optical frequency mapping (EOFM) have been reported in the literature, but photoelectric laser stimulation (PLS) gets little attention. Considering the potential advantages of PLS over other techniques (e.g., less power is required to generate current-voltage changes and the effect can be triggered at shorter wavelengths, which can lead to improved spatial resolution), the authors set out to determine if logic state images can be generated from various types of devices with PLS and assess the strengths and limitations for each case. The results of the investigation are presented in this paper.

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