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Amélioration d'attaques par canaux auxiliaires sur la cryptographie asymétrique

Abstract : : Since the 1990s, side channel attacks have challenged the security level of cryptographic algorithms on embedded devices. Indeed, each electronic component produces physical emanations, such as the electromagnetic radiation, the power consumption or the execution time. Besides, these emanations reveal some information on the internal state of the computation. A wise attacker can retrieve secret data in the embedded device using the analyzes of the involuntary “leakage”, that is side channel attacks. This thesis focuses on the security evaluation of asymmetric cryptographic algorithm such as RSA and ECC. In these algorithms, the main leakages are observed on the modular multiplication. This thesis presents two attacks targeting the modular multiplication in protected algorithms, and a formal demonstration of security level of a countermeasure named modular extension. A first attack is against scalar multiplication on elliptic curve implemented with a regular algorithm and scalar blinding. This attack uses a unique acquisition on the targeted device and few acquisitionson another similar device to retrieve the whole scalar. A horizontal leakage during the modular multiplication over large numbers allows to detect and correct easily an error bit in the scalar. A second attack exploits the final subtraction at the end of Montgomery modular multiplication. By studying the dependency of consecutive multiplications, we can exploit the information of presence or absence of final subtraction in order to defeat two protections : regular algorithm and blinding input values. Finally, we prove formally the security level of modular extension against first order fault attacks applied on elliptic curves cryptography.
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Submitted on : Monday, April 29, 2019 - 10:03:08 AM
Last modification on : Saturday, June 25, 2022 - 9:12:36 PM


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  • HAL Id : tel-02113704, version 1



Margaux Dugardin. Amélioration d'attaques par canaux auxiliaires sur la cryptographie asymétrique. Cryptographie et sécurité [cs.CR]. Télécom ParisTech, 2017. Français. ⟨NNT : 2017ENST0035⟩. ⟨tel-02113704⟩



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