Company Filing History:
Years Active: 2021-2024
Title: Innovations of Thomas Chabrier
Introduction
Thomas Chabrier is an accomplished inventor based in Courbevoie, France. He has made significant contributions to the field of cryptography, holding 2 patents that showcase his innovative approach to security measures against fault injection attacks.
Latest Patents
One of his latest patents is titled "Infective Countermeasures." This invention proposes a novel type of infective countermeasure against fault injection attacks. Instead of determining the injected error before amplifying it, the novel countermeasure applies the same diffusion function to two intermediate ciphers obtained by executing a cryptographic operation on an input. The error is therefore amplified within the same intermediate ciphers, referred to as infective ciphers after diffusion. It is then possible to use diffusion functions that do not map the cipher 0 as an output equal to 0. A cipher recomposed from bits of undiffused ciphers is also generated. These infective and recomposed ciphers are XOR-combined to provide an output cipher. This approach allows for the adaptation of the protection offered by the countermeasure to a desired number of injected faults through simple duplication of the pairs and associated specific diffusion functions.
Another significant patent is the "Method for Determining a Modular Inverse and Associated Cryptographic Processing Device." In this method, successive iterations are applied to two pairs, each including a first variable and a second variable. At the end of each iteration, the product of the second variable and the number is equal to the first variable modulo a given module. Each iteration includes at least one division by two of the first variable of a first pair or of a second pair, or a combination of the first variable of the first pair and of the first variable of the second pair by addition or subtraction. Some iterations include a step of storing the result of the combination in the first variable of a randomly determined pair.
Career Highlights
Thomas Chabrier is currently employed at Idemia France, where he continues to develop innovative solutions in the field of cryptography. His work focuses on enhancing security measures and improving the efficiency of cryptographic processes.
Collaborations
He collaborates with notable colleagues, including Gilles Piret and Laurent Castelnovi, who contribute to his projects and innovations.
Conclusion
Thomas Chabrier's contributions to cryptography through his patents demonstrate his commitment