Thoroughly analyzing the use of ring oscillators for on-chip hardware trojan detection

International audienceWith the globalization of the IC design flow, structural integrity verification to detect parasitic electrical activities has emerged as an important research domain for testing the genuineness of an Integrated Circuit (IC). Sensors like Ring Oscil-lators (RO) have been proposed to precisely monitor the internal behaviour of the ICs. In this paper we propose an experimental analysis of the impact of parasitic electrical activities on the frequencies of ROs and on the internal supply voltages measured. Our observations lead us to identify the limits of the usability of ROs for practical and embedded detection of Hardware Trojans

Extraction of intrinsic structure for Hardware Trojan detection

Cryptology ePrint Archive: Report 2015/912In this paper we present a novel solution to address the problem of potential malicious circuitry on FPGA. This method is based on an a technique of structure extraction which consider the infection of an all lot. This structure is related to the design (place and route, power grid...) of the integrated circuits which composes the lot. In case of additional circuitry this design will be modify and the extracted structure will be affected. After developing the extraction techniques we present a method- ology to insert detection of hardware trojan and counterfeit in different IC manufacturing steps. At last an application example using 30 FPGA boards validate our extraction method. Finally, statistical tools are then applied on the experimental results to distinguish a genuine lot from an infected one and confirm the potential of detection the extracted structure

Loss features in ultracold 162^{162}Dy gases: two- versus three-body processes

Dipolar gases like erbium and dysprosium have a dense spectrum of resonant loss features associated with their strong anisotropic interaction potential. These resonances display various behaviours with density and temperature, implying diverse microscopic properties. Here, we quantitatively investigate the low-field ($B < 6\,\text{G}$) loss features in ultracold thermal samples of $^{162}$Dy, revealing two- and three-body dominated loss processes. We investigate their temperature dependence and detect a feature compatible with a $d$-wave Fano-Feshbach resonance, which has not been observed before. We also analyse the expansion of the dipolar Bose-Einstein condensate as a function of the magnetic field and interpret the changes in size close to the resonances with a variation in the scattering length.Comment: 10 pages, 10 figure

Ellipse et coordination dans les grammaires de type logique

International audienceLes grammaires catégorielles (Lambek, Steedmann, Moortgat, Morrill) font partie d'un paradigme d'analyse des langues naturelles dit 'logiques sous-structurelles', i.e. logiques sensibles à la quantité et l'ordre des ressources disponibles. Elles ont théoriquement la souplesse pour gérer la manière dont nous utilisons cognitivement les ressources. Ces logiques bi-directionnelles ont accordé une grande importance à la non-commutativité des ressources (voire parfois à la non-associativité), confondant ainsi les deux niveaux de la grammaire, qualifiés de tectogrammatique (syntaxe abstraite) et phénogrammatique (forme phonologique) par Curry (1961). Ces logiques relativement rigides ne sont pas idéales pour traiter les phénomènes non linéaires et/ou non périphériques tels l'ellipse et la coordination. Plusieurs auteurs (Oehrle, Muskens) ont proposé d'en revenir à des systèmes commutatifs afin de pallier à la rigidité des systèmes bi-directionnels : le fardeau de l'ordre des mots est ainsi délégué au niveau proprement " phonologique ", tandis que l'agencement des catégories reste bien l'objet d'une logique. C'est dans cette orientation que nous nous situons ici

L'interface entre syntaxe et sémantique pour les grammaires minimalistes catégorielles

National audienceLes propositions [2] de systèmes déductifs décrivant les grammaires minimalistes d'Edward Stabler [3] permettent d'étudier l'interface syntaxe sémantique [1] . L'idée principale est que la forme logique n'est pas le résultat immédiat de la dérivation syntaxique mais qu'il existe une analyse sémantique construite en parallèle. Les deux analyses participent à la bonne formation de la phrases, en ceci que les dérivations correctes sont celles dont les deux pendants, syn-taxique et sémantique, sont synchronisés. Nous montrons ici comment l'utilisation de contextes permet cette synchronisation. Grammaires Minimalistes Catégorielles La fusion (merge) correspond aux règles clas-siques d'élimination de / et \ des grammaires catégorielles. Le déplacement (move), correspond à l'élimination du produit noté ×. Les règles du produit sont les suivantes, Γ x : A ∆ y : B [i×] Γ,∆ (x,y) : A × B Γ w : A × B ∆,x : A,y : B,∆ z : C [e×] ∆,Γ,∆ let(x,y) = (π 1 (w),π 2 (w))inz : C π 1 et π 2 sont les projections des deux composantes la contruction let u = v in w de la programmation fonctionnelle L'élimination du produit peut intervenir à tout moment dans la dérivation, dès que les hypo-thèses à décharger ont été introduites. En pratique, nous utilisons une règle avec trois prémisses, règles qui s'obtient à partir de celles ci-dessus: Γ w : A × B x : A x : A y : B,∆ y : B [e×] 3 Γ,∆ let(x,y) = (π 1 (w),π 2 (w))inz :

The EVIL Machine: Encode, Visualize and Interpret the Leakage

Unsupervised side-channel attacks allow extracting secret keys manipulated by cryptographic primitives through leakages of their physical implementations. As opposed to supervised attacks, they do not require a preliminary profiling of the target, constituting a broader threat since they imply weaker assumptions on the adversary model. Their downside is their requirement for some a priori knowledge on the leakage model of the device. On one hand, stochastic attacks such as the Linear Regression Analysis (LRA) allow for a flexible a priori, but are mostly limited to a univariate treatment of the traces. On the other hand, model-based attacks require an explicit formulation of the leakage model but have recently been extended to multidimensional versions allowing to benefit from the potential of Deep Learning (DL) techniques. The EVIL Machine Attack (EMA), introduced in this paper, aims at taking the best of both worlds. Inspired by generative adversarial networks, its architecture is able to recover a representation of the leakage model, which is then turned into a key distinguisher allowing flexible a priori. In addition, state-of-the-art DL techniques require 256 network trainings to conduct the attack. EMA requires only one, scaling down the time complexity of such attacks by a considerable factor. Simulations and real experiments show that EMA is applicable in cases where the adversary has very low knowledge on the leakage model, while significantly reducing the required number of traces compared to a classical LRA. Eventually, a generalization of EMA, able to deal with masked implementation is introduced

Revisiting Mutual Information Analysis: Multidimensionality, Neural Estimation and Optimality Proofs

Recent works showed how Mutual Information Neural Estimation (MINE) could be applied to side-channel analysis in order to evaluate the amount of leakage of an electronic device. One of the main advantages of MINE over classical estimation techniques is to enable the computation between high dimensional traces and a secret, which is relevant for leakage assessment. However, optimally exploiting this information in an attack context in order to retrieve a secret remains a non-trivial task especially when a profiling phase of the target is not allowed. Within this context, the purpose of this paper is to address this problem based on a simple idea: there are multiple leakage sources in side-channel traces and optimal attacks should necessarily exploit most/all of them. To this aim, a new mathematical framework, designed to bridge classical Mutual Information Analysis (MIA) and the multidimensional aspect of neural-based estimators, is proposed. One of the goals is to provide rigorous proofs consolidating the mathematical basis behind MIA, thus alleviating inconsistencies found in the state of the art. This framework allows to derive a new attack called Neural Estimated Mutual Information Analysis (NEMIA). To the best of our knowledge, it is the first unsupervised attack able to benefit from both the power of deep learning techniques and the valuable theoretical properties of MI. Simulations and experiments show that NEMIA outperforms classical and more recent deep learning based unsupervised side-channel attacks, especially in low-information contexts

Categorial Minimalist Grammar: From Generative Syntax To Logical Form

International audienceWe first recall some basic notions on minimalist grammars and on categorial grammars. Next we shortly introduce partially commutative linear logic, and our representation of minimalist grammars within this categorial system, the so-called categorial minimalist grammars. Thereafter we briefly present λμ-DRT (Discourse Representation Theory) an extension of λ-DRT (compositional DRT) in the framework of λμ calculus: it avoids type raising and derives different readings from a single semantic representation, in a setting which follows discourse structure. We run a complete example which illustrates the various structures and rules that are needed to derive a semantic representation from the categorial view of a transformational syntactic analysis

A rewriting of the relation between the acolinearity of annihilation photons and their energy in the context of positron emission tomography

Acolinearity of the annihilation photons observed in Positron Emission Tomography (PET) is described as following a Gaussian distribution. However, it is never explicitly said if it refers to the amplitude of the acolinearity angle or its 2D distribution relative to the case without acolinearity (herein defined as the acolinearity deviation). Since the former is obtained by integrating the latter, a wrong interpretation would lead to very different results. The paper of Shibuya et al. (2007), differs from the previous studies since it is based on the precise measurement of the energy of the annihilation photons. They also show that acolinearity follows a Gaussian distribution in the context of PET. However, their notation, which relies on being on the plane where the two annihilation photons travel, could mean that their observation refers to the amplitude of the acolinearity angle. If that understanding is correct, it would mean that acolinearity deviation follows a 2D Gaussian distribution divided by the norm of its argument. Thus, we revisited the proof presented in Shibuya et al. (2007) by using an explicit description of the acolinearity in the 3D unit sphere

Syntax and Semantics interacting in a Minimalist theory

International audienceAfter several proposals of a logical account of minimalism [5, 4, 6, 1], on the basis of the formalization provided by Edward Stabler [7, 8], we explore more precisely the interface between syntax and semantics. The main idea is that, according to many observations made for instance by Ray Jackendoff [3], the logical form is not the mere result of a derivation after the consumption of formal features. Indeed, there are rather two tasks which are performed on a par : the syntactic analysis properly speaking and the semantical analysis. Both analyses are connected by synchronization links in such a way that a parse can crash for (at least) two reasons : either because of a mismatch of syntactic features, or because of a failure in the semantic derivation