Jean-Denis Techer

Current mask generation: a transistor level security against DPA attacks

The physical implementation of cryptographic algorithms may leak to some attacker security information by the side channel data, as power consumption, timing, temperature or electromagnetic emanation. The differential power analysis (DPA) is a powerful side channel attack, based only on the power consumption information. There are some countermeasures proposed at algorithmic or architectural level that are expensive and/or complexes. This paper addresses the DPA attack problem by a novel and efficient transistor-level method based on a power consumption control, without any modification on the cryptographic algorithms, messages or keys

New implantable stimulator for the FES of paralyzed muscles

We propose a new implantable circuit for the internal functional electrical stimulation (FES) of motor nerves for paraplegic people. The circuit is designed to deliver precise calibrated stimulation pulses to specific multipolar electrodes. Several original design features have been developed to respond to the particular specifications imposed by safety constraints. In particular, the DAC has been thought to be fully monotonic and the output stage to ensure a passive and secure discharge of the safety capacitor. Also some features have been added in order to improve the classical charge pump that generates on-chip high voltage.

An implantable ASIC for neural stimulation

The integrated circuit proposed in this paper is dedicated to the neural stimulation of motor muscles for paraplegic people. For this kind of application, the constraints in terms of safety and performances are stringent. In practice our ASIC (application specific integrated circuit) allows us to deliver precise calibrated stimulation pulses to specific multi-polar electrode together with a very safety running cycle. In particular, the DAC has been thought to be fully monotonic and the output stage to ensure a passive and secure discharge of the safety capacitor. Also some tricky features have been added in order to improve the classical charge pump that generates on-chip high voltage.

Current Mask Generation: an Analog Circuit to Thwart DPA Attacks

This work addresses the leakage information problem concerning cryptographic circuits. Physical implementations of cryptographic algorithms may let escape some side channel information, like electromagnetic emanations, temperature, computing time, and power consumption. With this information, an attacker can retrieve the data that is being computed, like cryptographic keys. This paper proposes a novel method to thwart DPA attacks, based on power consumption control. As main contribution, this approach not requires any modification on the cryptographic algorithm, the messages or keys.