References of "Goubin, Louis"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailDefeating State-of-the-Art White-Box Countermeasures with Advanced Gray-Box Attacks
Goubin, Louis; Rivain, Matthieu UL; Wang, Junwei UL

in IACR Transactions on Cryptographic Hardware and Embedded Systems (2020), 2020(3), 454482

The goal of white-box cryptography is to protect secret keys embedded in a cryptographic software deployed in an untrusted environment. In this article, we revisit state-of-the-art countermeasures ... [more ▼]

The goal of white-box cryptography is to protect secret keys embedded in a cryptographic software deployed in an untrusted environment. In this article, we revisit state-of-the-art countermeasures employed in white-box cryptography, and we discuss possible ways to combine them. Then we analyze the different gray-box attack paths and study their performances in terms of required traces and computation time. Afterward, we propose a new paradigm for the gray-box attack against white-box cryptography, which exploits the data-dependency of the target implementation. We demonstrate that our approach provides substantial complexity improvements over the existing attacks. Finally, we showcase this new technique by breaking the three winning AES-128 white-box implementations from WhibOx 2019 white-box cryptography competition. [less ▲]

Detailed reference viewed: 163 (1 UL)
Full Text
Peer Reviewed
See detailHow to reveal the secrets of an obscure white-box implementation
Goubin, Louis; Paillier, Pascal; Rivain, Matthieu UL et al

in Journal of Cryptographic Engineering (2019), 10(1), 49--66

White-box cryptography protects key extraction from software implementations of cryptographic primitives. It is widely deployed in DRM and mobile payment applications in which a malicious attacker might ... [more ▼]

White-box cryptography protects key extraction from software implementations of cryptographic primitives. It is widely deployed in DRM and mobile payment applications in which a malicious attacker might control the entire execution environment. So far, no provably secure white- box implementation of AES has been put forward, and all the published practical constructions are vulnerable to differential computation analysis (DCA) and differential fault analysis (DFA). As a consequence, the industry relies on home-made obscure white-box implementations based on secret designs. It is therefore of interest to investigate the achievable resistance of an AES implementation to thwart a white-box adversary in this paradigm. To this purpose, the ECRYPT CSA project has organized the WhibOx contest as the catch the flag challenge of CHES 2017. Researchers and engineers were invited to participate either as designers by submitting the source code of an AES-128 white-box implementation with a freely chosen key, or as breakers by trying to extract the hard-coded keys in the submitted challenges. The participants were not expected to disclose their identities or the underlying designing/attacking techniques. In the end, 94 submitted challenges were all broken and only 13 of them held more than 1 day. The strongest (in terms of surviving time) implementation, submitted by Biryukov and Udovenko, survived for 28 days (which is more than twice as much as the second strongest implementation), and it was broken by a single team, i.e., the authors of the present paper, with reverse engineering and algebraic analysis. In this paper, we give a detailed description of the different steps of our cryptanalysis. We then generalize it to an attack methodology to break further obscure white-box implementations. In particular, we formalize and generalize the linear decoding analysis that we use to extract the key from the encoded intermediate variables of the target challenge. [less ▲]

Detailed reference viewed: 58 (3 UL)