Attack on a DFA protected AES by simultaneous laser fault injections

This paper demonstrates a Fault Attack on an AES core protected by an infection type countermeasure. The redundant AES is implemented on a Xilinx Spartan-6FPGA, with a feature size of 45 nm. By injecting exactly the same fault in both state registers of the redundant implementation using lasers, we are able to annul the protection added by the countermeasure and thus perform a successful Differential Fault Analysis. This requires a high precision double laser setup in order to hit two different locations on the chip at the same point in time. With a priori knowledge about the location of both state registers, we were able to generate applicable faultyciphertexts within minutes. Our results show that for applications demanding a high level of security, relying on a duplication of hardware is not sufficient

Locked out by Latch-up? An Empirical Study on Laser Fault Injection into Arm Cortex-M Processors

Laser-based fault injection (LFI) is considered as one of the most powerful tools for active attacks against integrated circuits. However, only few empirical results are published for LFI into modern low-power microcontrollers with current process technologies. To fill this gap, we investigate LFI in four Cortex-M microcontrollers from different manufacturers: ST Microelectronics, NXP and Infineon. We note that those controllers differ from the ones used in high-security smartcard devices but argue that they are possibly built in similar process technologies making our results relevant for security evaluations. We were able to successfully inject precise faults into either the SRAM or the register file in all tested devices. We report our settings and fault maps in order to facilitate further fault attack investigations on these microcontrollers. As another contribution, we would like to emphasize the significant difficulties we encountered in some measurements due to the occurrence of latch-up effects. In many cases, the latch-up behavior of the integrated circuit prevented successful fault injections. This observation is largely underrepresented in scientific publications, which leads to an overestimation of the effectiveness of laser-based fault injection attacks under realistic circumstances

The Molten Globule State of Maltose-Binding Protein: Structural and Thermodynamic Characterization by EPR Spectroscopy and Isothermal Titration Calorimetry

Employing site-directed spin labeling (SDSL), the structure of maltose-binding protein (MBP) had previously been studied in the native state by electron paramagnetic resonance (EPR) spectroscopy. Several spin-labeled double cysteine mutants were distributed all over the structure of this cysteine-free protein and revealed distance information between the nitroxide residues from double electron–electron resonance (DEER). The results were in good agreement with the known X-ray structure. We have now extended these studies to the molten globule (MG) state, a folding intermediate, which can be stabilized around pH 3 and that is characterized by secondary but hardly any tertiary structure. Instead of clearly defined distance features as found in the native state, several additional characteristics indicate that the MG structure of MBP contains different polypeptide chain and domain orientations. MBP is also known to bind its substrate maltose even in MG state although with lower affinity. Additionally, we have now created new mutants allowing for spin labeling at or near the active site. Our data confirm an already preformed ligand site structure in the MG explaining its substrate binding capability and thus most probably serving as a nucleation center for the final native structure