Description
Cryptographic algorithms are primarily designed to be secure in the black-box model, where an attacker can only observe their input/output behavior. However in practice, algorithms are rarely executed in a completely isolated environment and additional information is often leaked. In the context of mobile applications or connected objects, devices often lack secure storage to protect secret keys, and their generally open execution environment exposes a large attack surface. This hostile environment is captured by the white-box attack model. While many white-box implementation of block ciphers have been published since 2002, asymmetric cryptosystems have been very little studied. In my PhD thesis, we got interested in white-box implementations of ECDSA. This led us to participate in the WhibOx Contest that was organized as part of the TCHES workshops in 2021. During three months, developpers were invited to submit ECDSA white-box implementations and attackers to try to break them. In this talk, I will introduce the white-box model before explaining the specificities of the ECDSA algorithm in this context. I will then present the different attacks that we used to break almost all the challenges of the WhibOx Contest.
Next sessions
-
SoK: Security of the Ascon Modes
Speaker : Charlotte Lefevre - Radboud University
The Ascon authenticated encryption scheme and hash function of Dobraunig et al (Journal of Cryptology 2021) were recently selected as winner of the NIST lightweight cryptography competition. The mode underlying Ascon authenticated encryption (Ascon-AE) resembles ideas of SpongeWrap, but not quite, and various works have investigated the generic security of Ascon-AE, all covering different attack[…] -
Comprehensive Modelling of Power Noise via Gaussian Processes with Applications to True Random Number Generators
Speaker : Maciej Skorski - Laboratoire Hubert Curien
The talk examines power noise modelling through Gaussian Processes for secure True Random Number Generators. While revisiting one-sided fractional Brownian motion, we obtain novel contributions by quantifying posterior uncertainty in exact analytical form, establishing quasi-stationary properties, and developing rigorous time-frequency analysis. These results are applied to model oscillator[…]-
Cryptography
-
TRNG
-
-
CryptoVerif: a computationally-sound security protocol verifier
Speaker : Bruno Blanchet - Inria
CryptoVerif is a security protocol verifier sound in the computational model of cryptography. It produces proofs by sequences of games, like those done manually by cryptographers. It has an automatic proof strategy and can also be guided by the user. It provides a generic method for specifying security assumptions on many cryptographic primitives, and can prove secrecy, authentication, and[…]-
Cryptography
-