Physical attacks aim at extracting secret information from an electronic device. Besides the passive side channel analysis, which restrict on observing the environment of the device, there are also active attacks, so called fault attacks, which try to distrub the device in an applicable manner. In combination with knowledge about the working principle of a cryptographic algorithm, the deliberatly inducted faults can be exploited to gather information about the internally used secrect key.
In order to inject faults, various techniques are effective. Common methods are based on driving a device outside its specified operational conditions (supply voltage level, system clock frequency or temperature). Beyond that, there are more complex techniques like e.g. Laser-based Fault Injection. Focused laser light causes a photo-electric effect which enables to induce faults at a very high precision (temporal and local). This gives the attacker more control and enables to perform a wider range of attacks.
In our hardware test lab we have two different laser stations to carry out fault attacks and evaluate the security of specific devices or countermeasures.