Idemia France

Franck Rondepierre

Luk Bettale

Christophe Giraud

Emmanuelle Dottax

Michele Sartori

Alberto Battistello

Guillaume Barbu

Jean-Philippe Vallieres

Nicolas Debande

Aurélien Greuet

Florian Galdo

Clémence Vermeersch

Rina Zeitoun

Sarah Lopez

A cryptographic processing method comprises the following steps:

Cryptographic processing method, related electronic device and computer program

Disclosed is a method of verifying integrity of a pair of public and private cryptographic keys within the additive group of the integers modulo N, with N being the product of two primary numbers p and q, the method including: calculating a candidate private exponent d' corresponding to a private exponent d of the private key; and executing a test of integrity. The test of integrity includes a step for verifying the coherence of the candidate private exponent d&#x2032; with respect to a public exponent e of the public key and to the numbers p and q, the verification step involving a first multiple modulo of the public exponent e of the public key and a second multiple modulo of the public exponent e of the public key.

Method of verifying integrity of a pair of cryptographic keys and cryptographic device

A method for cryptographic processing includes: storing an initial value as the current value; implementing a predetermined number of first steps, including one involving obtaining second data by applying a first cryptographic algorithm to first data, the others each involving the application of the first cryptographic algorithm to the current value and the storage of the result as the new current value; implementation of the predetermined number of second steps, including one involving the obtaining of fourth data by applying, to third data, a second cryptographic algorithm that is the inverse of the first cryptographic algorithm, the others each involving the application of the second cryptographic algorithm to the current value and the storage of the result as the new current value; and verification of the equality of the first data and the fourth data, and of the equality of the current value and the initial value.

Method and device for cryptographic processing of data

An electronic device is proposed, which is configured to receive at least one cryptographic parameter and validate the at least one cryptographic parameter. The electronic device is is configured to validating the parameter by determining an imprint from a one-way function and from at least the cryptographic parameter; detecting at least one part of the imprint in a dedicated memory zone of the electronic device, and delivering a piece of information on validation should there be effective detection.

Method for validating a cryptographic parameter and corresponding device

Growing community of inventors

Courbevoie, France

Franck Rondepierre