On the Security of the (F)HMQV Protocol

International audienceThe HMQV protocol is under consideration for IEEE P1363 standardization. We provide a complementary analysis of the HMQV protocol. Namely, we point a Key Compromise Impersonation (KCI) attack showing that the two and three pass HMQV protocols cannot achieve their security goals. Next, we revisit the FHMQV building blocks, design and security arguments; we clarify the security and efficiency separation between HMQV and FHMQV, showing the advantages of FH-MQV over HMQV

SPAE un schéma opératoire pour l'AES sur du matériel bas-coût.

We propose SPAE, a single pass, patent free, authenticated encryption with associated data (AEAD) for AES. The algorithm has been developped to address the needs of a growing trend in IoT systems: storing code and data on a low cost flash memory external to the main SOC. Existing AEAD algorithms such as OCB, GCM, CCM, EAX , SIV, provide the required functionality however in practice each of them suffer from various drawbacks for this particular use case. Academic contributions such as ASCON and AEGIS-128 are suitable and efficient however they require the development of new hardware accelerators and they use primitives which are not 'approved' by governemental institutions such as NIST, BSI, ANSSI. From a silicon manufacturer point of view, an efficient AEAD which use existing AES hardware is much more enticing: the AES is required already by most industry standards invovling symmetric encryption (GSMA, EMVco, FIDO, Bluetooth, ZigBee to name few). This paper expose the properties of an ideal AEAD for external memory encryption, present the SPAE algorithm and analyze various security aspects. Performances of SPAE on actual hardware are better than OCB, GCM and CCM.Nous présentons SPAE, un schéma en une passe, libre de droit, d'encryption authentifiée avec données associées (AEAD) appliqué à l'AES. Cet algorithme a été développé afin de répondre à une tendance grandissante dans l'internet des objets: stocker du code et des données sur une mémoire flash à bas coût externe au système sur puce (SOC). Des algorithmes AEAD existent déjà tels que OCB, GCM, CCM, EAX, SIV, ils répondent à l'usage demandé cependant en pratique chacun de ces algorithmes présente des désavantages pour cet usage particulier. Les contributions académique telles que ASCON et AEGIS-128 sont appropriés et efficaces cependant ils nécessitent le développement de nouveaux accélérateurs matériels et ils utilisent des primitives qui ne sont pas approuvés par les instituions gouvernementales telles que le NIST, BSI ANSSI. Du point de vue du fabricant de silicone, un AEAD efficace qui utilise du matériel AES existant est beaucoup plus attirant: l'AES est déjà requis par la plupart des standards industriels utilisant de l’encryption symétrique (GSMA, EMVco, FIDO, Bluetooth, ZigBee par exemple). Cet article montre les propriétés d'un AEAD idéal pour de la mémoire encryptée externe, présente l'algorithme SPAE et analyse plusieurs aspects de sécurité. Les performances de SPAE sur du matériel actuel sont meilleures que sur OCB, GCM, et CCM

Methodology for the Fault Analysis and Evaluation of True Random Number Generators

15 pages (double columns)True Random Number Generators have many uses, in particular they play a key role in security applications and cryptographic algorithms. Our interest lies in the quality of their generated random numbers. More specifically, for such utilizations, a slight deviation of the numbers from a "per- fect" behavior can have disastrous consequences. It is then necessary to devise schemes for the testing of these genera- tors in order to detect non-random properties of their num- bers. Moreover, one should consider them from an attacker point of view and use any means to try to perturbate their good functionnality. In this article we describe such exper- iments and several standard statistical tools for the genera- tors testing. We also present experimental results obtained through the study of a generator embedded in a processor in order to illustrate our methodology. We show that its pertu- bation leads to the apparition of dangerous deviations in its numbers distribution

Fine-Grained Static Detection of Obfuscation Transforms Using Ensemble-Learning and Semantic Reasoning

International audienceThe ability to efficiently detect the software protections used is at a prime to facilitate the selection and application of adequate deob-fuscation techniques. We present a novel approach that combines semantic reasoning techniques with ensemble learning classification for the purpose of providing a static detection framework for obfuscation transformations. By contrast to existing work, we provide a methodology that can detect multiple layers of obfuscation, without depending on knowledge of the underlying functionality of the training-set used. We also extend our work to detect constructions of obfuscation transformations, thus providing a fine-grained methodology. To that end, we provide several studies for the best practices of the use of machine learning techniques for a scalable and efficient model. According to our experimental results and evaluations on obfuscators such as Tigress and OLLVM, our models have up to 91% accuracy on state-of-the-art obfuscation transformations. Our overall accuracies for their constructions are up to 100%

VORONOI COMPLEXES IN HIGHER DIMENSIONS, COHOMOLOGY OF GLN(Z)GL_N (Z) FOR N≥8N\ge 8 AND THE TRIVIALITY OF K8(Z)K_8 (Z)

We enumerate the low dimensional cells in the Voronoi cell complexes attached to the modular groups $SL_N (Z)$ and $GL_N (Z)$ for $N = 8, 9, 10, 11$, using quotient sublattices techniques for $N = 8, 9$ and linear programming methods for higher dimensions. These enumerations allow us to compute some cohomology of these groups and prove that $K_8 (Z) = 0$, providing new knowledge on the Kummer-Vandiver conjecture

Defeating Opaque Predicates Statically through Machine Learning and Binary Analysis

International audienceWe present a new approach that bridges binary analysis techniques with machine learning classification for the purpose of providing a static and generic evaluation technique for opaque predicates, regardless of their constructions. We use this technique as a static automated deobfuscation tool to remove the opaque predicates introduced by obfuscation mechanisms. According to our experimental results, our models have up to 98% accuracy at detecting and deob-fuscating state-of-the-art opaque predicates patterns. By contrast, the leading edge deobfuscation methods based on symbolic execution show less accuracy mostly due to the SMT solvers constraints and the lack of scalability of dynamic symbolic analyses. Our approach underlines the efficiency of hybrid symbolic analysis and machine learning techniques for a static and generic deobfuscation methodology