Launched in 2021, the ASCRIPT project (Safety Analysis of Integrated Circuits by PhotoThermal Effect) has come to an end, resulting in the improvement of analysis techniques, such as the TLS (Thermal Laser Stimulation) technique.

The constant progress of test and integration technologies

The constant progress of test and integration technologies, the spread of attacks tools that are increasingly accessible to malicious organizations, and the addition of connectivity in new, so-called sensitive systems, are forcing stakeholders to improve the techniques used for integrated circuit design and safety.

This was the background to the ASCRIPT project. Funded by the Agence de l'Innovation Défense (AID) and in partnership with SERMA, the aim of this project was to develop new methods of evaluation and safety improvements for integrated circuits concernning an imaging technique that uses a laser as a heat source.

Each partner played a specific role in this project. SERMA was responsible for preparing the targets, defining the attack scenarios and analyzing the results. For its part, ALPhANOV carried out in-depth scientific monitoring and state of the art to draw up a precise set of specifications and then, assembled a demonstrator proving the effectiveness of this technique.

New security assessment and enhancement methods based on TLS technology

The TLS technique (Thermal Laser Stimulation) relies on the use of a laser beam focused on a target transistor, which generates a localized heat source. This rise in temperature leads to variations in electrical consumption of the order of a few tens of nA (nanoamps), depending on the state of the transistor. Then, by scanning each transistor making up a memory, it becomes possible to retrieve its content.

ALPhANOV also integrated a galvanometric scanner on a microscope station and, in collaboration with AeroDIODE, designed a laser source perfectly suited to this application, following numerous comparative tests. Simultaneously, a software solution was developed to ensure intuitive experience with the equipment - from the selection of areas of interest to the reconstruction and observation of data.

These combined innovations have reduced acquisition time by a factor of 40 and improved mechanical stability, simplifying post-processing and eliminating the need for frequent data realignments. Tests on targets of various technologies have shown that this technique, while effective and paving the way for safer, more resilient systems in the face of attack, remains limited to targets that can be configured in very deep sleep states, with power consumptions of less than µA.