Power Side Channels in Security ICs: Hardware Countermeasures

Power side-channel attacks are a very effective cryptanalysis technique that can infer secret keys of security ICs by monitoring the power consumption. Since the emergence of practical attacks in the late 90s, they have been a major threat to many cryptographic-equipped devices including smart cards, encrypted FPGA designs, and mobile phones. Designers and manufacturers of cryptographic devices have in response developed various countermeasures for protection. Attacking methods have also evolved to counteract resistant implementations. This paper reviews foundational power analysis attack techniques and examines a variety of hardware design mitigations. The aim is to highlight exposed vulnerabilities in hardware-based countermeasures for future more secure implementations

Design and analysis of an FPGA-based, multi-processor HW-SW system for SCC applications

The last 30 years have seen an increase in the complexity of embedded systems from a collection of simple circuits to systems consisting of multiple processors managing a wide variety of devices. This ever increasing complexity frequently requires that high assurance, fail-safe and secure design techniques be applied to protect against possible failures and breaches. To facilitate the implementation of these embedded systems in an efficient way, the FPGA industry recently created new families of devices. New features added to these devices include anti-tamper monitoring, bit stream encryption, and optimized routing architectures for physical and functional logic partition isolation. These devices have high capacities and are capable of implementing processors using their reprogrammable logic structures. This allows for an unprecedented level of hardware and software interaction within a single FPGA chip. High assurance and fail-safe systems can now be implemented within the reconfigurable hardware fabric of an FPGA, enabling these systems to maintain flexibility and achieve high performance while providing a high level of data security. The objective of this thesis was to design and analyze an FPGA-based system containing two isolated, softcore Nios processors that share data through two crypto-engines. FPGA-based single-chip cryptographic (SCC) techniques were employed to ensure proper component isolation when the design is placed on a device supporting the appropriate security primitives. Each crypto-engine is an implementation of the Advanced Encryption Standard (AES), operating in Galois/Counter Mode (GCM) for both encryption and authentication. The features of the microprocessors and architectures of the AES crypto-engines were varied with the goal of determining combinations which best target high performance, minimal hardware usage, or a combination of the two

Stream ciphers for secure display

In any situation where private, proprietary or highly confidential material is being dealt with, the need to consider aspects of data security has grown ever more important. It is usual to secure such data from its source, over networks and on to the intended recipient. However, data security considerations typically stop at the recipient's processor, leaving connections to a display transmitting raw data which is increasingly in a digital format and of value to an adversary. With a progression to wireless display technologies the prominence of this vulnerability is set to rise, making the implementation of 'secure display' increasingly desirable. Secure display takes aspects of data security right to the display panel itself, potentially minimising the cost, component count and thickness of the final product. Recent developments in display technologies should help make this integration possible. However, the processing of large quantities of time-sensitive data presents a significant challenge in such resource constrained environments. Efficient high- throughput decryption is a crucial aspect of the implementation of secure display and one for which the widely used and well understood block cipher may not be best suited. Stream ciphers present a promising alternative and a number of strong candidate algorithms potentially offer the hardware speed and efficiency required. In the past, similar stream ciphers have suffered from algorithmic vulnerabilities. Although these new-generation designs have done much to respond to this concern, the relatively short 80-bit key lengths of some proposed hardware candidates, when combined with ever-advancing computational power, leads to the thesis identifying exhaustive search of key space as a potential attack vector. To determine the value of protection afforded by such short key lengths a unique hardware key search engine for stream ciphers is developed that makes use of an appropriate data element to improve search efficiency. The simulations from this system indicate that the proposed key lengths may be insufficient for applications where data is of long-term or high value. It is suggested that for the concept of secure display to be accepted, a longer key length should be used

Security in automotive microcontrollers of next generation

Information technology – we define broadly as being systems based on digital hardware and software – has gained central importance for many new automotive applications and services.On the production side we observe that the cost for electronics and IT is approaching the 50% threshold of all manufacturing costs.One aspect of modern IT systems has hardly been addressed in the context of automotive applications: IT security. Security is concerned with protection against the manipulation of IT systems by humans. After a brief review of the evolution in the last five years of the IT security in the automotive environment, we will see the state of art of the security features of the automotive microcontrollers.laslty it will be presented an hardware module that ensure the privacy aspect, of the IT security, in a bus communication in an automotive environment

Cryptographic key distribution in wireless sensor networks: a hardware perspective

In this work the suitability of different methods of symmetric key distribution for application in wireless sensor networks are discussed. Each method is considered in terms of its security implications for the network. It is concluded that an asymmetric scheme is the optimum choice for key distribution. In particular, Identity-Based Cryptography (IBC) is proposed as the most suitable of the various asymmetric approaches. A protocol for key distribution using identity based Non-Interactive Key Distribution Scheme (NIKDS) and Identity-Based Signature (IBS) scheme is presented. The protocol is analysed on the ARM920T processor and measurements were taken for the run time and energy of its components parts. It was found that the Tate pairing component of the NIKDS consumes significants amounts of energy, and so it should be ported to hardware. An accelerator was implemented in 65nm Complementary Metal Oxide Silicon (CMOS) technology and area, timing and energy figures have been obtained for the design. Initial results indicate that a hardware implementation of IBC would meet the strict energy constraint of a wireless sensor network node

Studies on high-speed hardware implementation of cryptographic algorithms

Cryptographic algorithms are ubiquitous in modern communication systems where they have a central role in ensuring information security. This thesis studies efficient implementation of certain widely-used cryptographic algorithms. Cryptographic algorithms are computationally demanding and software-based implementations are often too slow or power consuming which yields a need for hardware implementation. Field Programmable Gate Arrays (FPGAs) are programmable logic devices which have proven to be highly feasible implementation platforms for cryptographic algorithms because they provide both speed and programmability. Hence, the use of FPGAs for cryptography has been intensively studied in the research community and FPGAs are also the primary implementation platforms in this thesis. This thesis presents techniques allowing faster implementations than existing ones. Such techniques are necessary in order to use high-security cryptographic algorithms in applications requiring high data rates, for example, in heavily loaded network servers. The focus is on Advanced Encryption Standard (AES), the most commonly used secret-key cryptographic algorithm, and Elliptic Curve Cryptography (ECC), public-key cryptographic algorithms which have gained popularity in the recent years and are replacing traditional public-key cryptosystems, such as RSA. Because these algorithms are well-defined and widely-used, the results of this thesis can be directly applied in practice. The contributions of this thesis include improvements to both algorithms and techniques for implementing them. Algorithms are modified in order to make them more suitable for hardware implementation, especially, focusing on increasing parallelism. Several FPGA implementations exploiting these modifications are presented in the thesis including some of the fastest implementations available in the literature. The most important contributions of this thesis relate to ECC and, specifically, to a family of elliptic curves providing faster computations called Koblitz curves. The results of this thesis can, in their part, enable increasing use of cryptographic algorithms in various practical applications where high computation speed is an issue

Aeronautical engineering: A continuing bibliography, supplement 122

This bibliography lists 303 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1980

Étude expérimentale de la micro-fracturation dans les roches et les interfaces roche-mortier sous chargement de traction directe et indirecte

Abstract: Fracture initiation and propagation at a large scale may cause catastrophic failure of many civil, mining, and petroleum engineering structures. It has been recognized that macroscopic fractures are produced by the initiation, propagation, and coalescence of many microcracks in a localized region around pre-existing micro-flaws called the fracture process zone (FPZ). On the other hand, as the rock materials are weaker in tension than in compression and shear, the development of FPZ and microcracking mechanisms under tensile loading are of primary interest. Natural hazards such as rock bursts and rockslides are related to the nucleation and growth of tensile cracks in rocks. Tensile strength and tensile fracturing are equally important in controlling rock-concrete structures. For instance, the tensile strength existing in the dam-foundation interface resists the overturning moment at the toe zone of the dam due to the acting forces of the reservoir. Besides, in some applications, both the extend of the FPZ, and the roughness characteristics of the created fractures are of critical importance. For instance, in hydraulic fracturing, the FPZ and fracture roughness are the two concepts that describe the complexity and the connectivity of the fractured reservoir rock. Therefore, the development of the FPZ or new fracture network in rocks not only impacts their mechanical properties (e.g., strength) but also affects their hydraulic characteristics (e.g., permeability). To date, extensive research has been carried out on the strength and fracturing properties of both intact rocks and rock-concrete interfaces under compression and shear loads. However, the microcracking processes and mechanisms and the relationship between micro- and macro-fracturing in rock and rock-concrete interfaces under tensile loading have not been well studied yet. Therefore, this thesis investigates the microcracking processes and micro-fracturing mechanisms in rock and rock-mortar specimens under direct and indirect (Brazilian) tensile loadings. In particular, it aims to (1) identify and describe the micromechanics of damage and the evolution of the fracture process zone in granite under indirect (Brazilian) tensile loading, (2) determine the effect of two loading rates on granite’s micro- and macro-fracturing behaviour and strength under indirect (Brazilian) tensile loading, (3) characterize the roughness of the surface failure of granite specimens in indirect (Brazilian) and direct tensile loading, (4) identify and describe the micromechanics of damage in direct tensile loadings in an attempt to explain the difference between strength values obtained from direct and indirect (Brazilian) tensile tests, and (5) identify and describe the micromechanics of damage at granite-mortar interface subjected to both direct and indirect (Brazilian) tensile loadings. To this end, acoustic emission (AE) and digital image correlation (DIC) techniques were employed to monitor the fracturing processes in laboratory-scale specimens of intact granite and granite-mortar tested under direct and Brazilian tensile loading. Specimens included (1) cylindrical disc specimens with a diameter of 75 mm and a thickness of 37.5 mm for Brazilian tests and (2) rectangular prismatic specimens with dimensions of 100 × 37 × 30 mm for direct tension tests. Our results showed consistency between the FPZs obtained from AE and DIC data for all tested specimens; however, AE provided a slightly larger process zone. AE results indicated that the microcracking within the FPZ might initiate under tensile, shear, or a combination of both mechanisms for specimens tested under direct and Brazilian tensile loadings. It was also shown that reducing the loading rate in the Brazilian tests (1) reduced the tensile strength and (2) increased the extent of the FPZ, meaning that both tensile strength and the FPZ are significantly affected by the tensile loading rate. In addition, the results showed that the direct tensile strength of the specimens is lower than their indirect tensile strength, with a direct/indirect tensile strength ratio of 66% for granite-mortar specimens and 70% for intact granite specimens. This indicates that this ratio for rock-mortar specimens remains in the same range as for intact rocks, at least for materials tested and under the experimental setup used in this research. To date, the relationship between direct and Brazilian tensile strengths of rock-mortar specimens has not been reported in the literature. The moment tensor inversion of the AE waveforms and the DIC strain field data showed that the generated macroscopic fractures, which are conventionally regarded as tensile fractures, were composed of tensile, shear, and compressive cracking mechanisms at the microscale. This was true for both intact and bi-material specimens tested under direct and indirect (Brazilian) tensile loadings. However, different microcracking mechanisms had different contributions (proportions) to the formation of the final macro-fractures. As for intact granite specimens, the ultimate so-called tensile macro-fracture was predominantly composed of shear microcracks in Brazilian tests and of tensile microcracks in the direct tension tests. Similarly, it was observed that a significant number of shear microcracks occurred in the granite-mortar specimens subjected to the Brazilian test. On the contrary, shear microcracks played a minimal role in the formation of the final macro-fractures in granite-mortar specimens under direct tension. Shear microcracks have higher strength than tensile microcracks and require higher energy to break. Thus, the higher contribution of shear microcracks (with a higher strength) to the formation of the ultimate macro-fracture in Brazilian specimens (both intact and granite-mortar) explains why specimens’ tensile strength obtained from the Brazilian test is higher than that obtained from direct tension test. Furthermore, it was observed that the microcracking mechanisms in all tested specimens might critically be influenced by (1) the compressive stress state in the Brazilian test due to its biaxial stress field and (2) the material type. Reducing the confinement and changing the material type (coursed-grain granite to fine-grained mortar) decreases the contribution of shear microcracks during the specimens' fracturing process, leading to a lower overall tensile strength. The effect of material type on microcracking mechanisms was seen for both direct and Brazilian tensile tests. In addition, it was shown that the loading rate significantly influences the microcracking mechanisms in granite discs under the Brazilian loading condition. It was also observed that the surface roughness of the generated macroscopic fractures in intact specimens increases with (a) reducing the loading rate and (b) increasing the grain size. In addition, the ultimate macroscopic fractures showed lower roughness with flatter surfaces in rock-mortar specimens tested under indirect (Brazilian) tension than those tested under direct tension. In general, it was clearly observed that different microcracking mechanisms (i.e., different contributions of shear, tensile, and compressive microcracks) (1) explain the difference between direct and Brazilian tensile strengths of tested materials and (2) determine the surface roughness of the produced macro-fractures under direct and Brazilian tests. In rock engineering projects, due to the difficulties in sample preparation and test execution in direct tensile tests, the tensile strength of rock-like materials is mostly measured indirectly by the Brazilian test. Because of the presence of shear microcracks in specimens tested under Brazilian loading, the obtained Brazilian strength overestimates the direct tensile strength of materials for both intact and granite-mortar specimens. It is believed that the direct tensile test provides values representing the true tensile strength of materials. But the tensile strength obtained from a direct tensile test is invariably applied in engineering projects with stress gradients. On the other hand, the disc material in a Brazilian test undergoes both stress gradients and biaxial stress fields, better representing the stress state in a rock mass when a tensile failure occurs in situ. Therefore, the question is how to determine the tensile strength of brittle materials. More precisely, which test configuration should be regarded as providing the true measure of the tensile strength?L'initiation et la propagation de fractures à grande échelle peuvent entraîner une défaillance catastrophique de nombreuses structures de génie civil, minier et pétrolier. Il a été reconnu que les fractures macroscopiques sont produites par l'initiation, la propagation et la coalescence de nombreuses microfissures dans une région localisée autour de micro-défauts préexistants appelée zone de processus de fracture (ZPF). D'autre part, les matériaux rocheux étant plus faibles en traction qu'en compression et en cisaillement, le développement des mécanismes de ZPF et de microfissuration sous chargement en traction est d'un intérêt primordial. Les risques naturels tels que les coups de roche et les glissements de terrain sont liés à la nucléation et à la croissance de fissures de traction dans les roches. La résistance à la traction et la fracturation en traction sont tout aussi importantes dans le contrôle des structures en béton de roche. Par exemple, la résistance à la traction existant dans l'interface barrage-fondation résiste au moment de renversement dans la zone du pied du barrage en raison des forces agissantes du réservoir. En outre, dans certaines applications, l'étendue de la ZPF et les caractéristiques de rugosité des fractures créées sont d'une importance critique. Par exemple, en fracturation hydraulique, la ZPF et la rugosité de fracture sont les deux concepts qui décrivent la complexité et la connectivité de la roche réservoir fracturée. Par conséquent, le développement de la ZPF ou du nouveau réseau de fractures dans les roches a non seulement un impact sur leurs propriétés mécaniques (par exemple, la résistance), mais également sur leurs caractéristiques hydrauliques (par exemple, la perméabilité). À ce jour, des recherches approfondies ont été menées sur la résistance et les propriétés de fracturation des roches intactes et des interfaces roche-béton sous des charges de compression et de cisaillement. Cependant, les processus et mécanismes de microfissuration et la relation entre la micro- et la macro-fracturation dans les interfaces roche et roche-béton sous chargement de traction n'ont pas encore été bien étudiés. Par conséquent, cette thèse étudie les processus de microfissuration et les mécanismes de micro-fracturation dans les spécimens de roche et de mortier rocheux sous des charges de traction directes et indirectes (brésiliennes). En particulier, il vise à (1) identifier et décrire la micromécanique de l'endommagement et l'évolution de la zone de processus de rupture dans le granite sous chargement de traction indirecte (brésilienne), (2) déterminer l'effet de deux taux de chargement sur les micro- et macro- et -comportement à la fracturation et résistance sous charge de traction indirecte (brésilienne), (3) caractériser la rugosité de la rupture de surface d'éprouvettes de granit sous charge de traction indirecte (brésilienne) et directe, (4) identifier et décrire la micromécanique de l'endommagement sous charge de traction directe dans une tentative d'expliquer la différence entre les valeurs de résistance obtenues à partir d'essais de traction directs et indirects (brésiliens), et (5) identifier et décrire la micromécanique des dommages à l'interface granit-mortier soumis à des charges de traction directes et indirectes (brésiliennes). À cette fin, des techniques d'émission acoustique (EA) et de corrélation d'images numériques (CIN) ont été utilisées pour surveiller les processus de fracturation dans des spécimens à l'échelle du laboratoire de granit intact et de mortier de granit testés sous une charge de traction directe et brésilienne. Les spécimens comprenaient (1) des spécimens de disques cylindriques d'un diamètre de 75 mm et d'une épaisseur de 37,5 mm pour les essais brésiliens et (2) des spécimens prismatiques rectangulaires de dimensions 100 × 37 × 30 mm pour les essais de tension directe. Nos résultats ont montré une cohérence entre les ZPF obtenus à partir des données EA et CIN pour tous les spécimens testés ; cependant, EA a fourni une zone de traitement légèrement plus grande. Les résultats de l'EA ont indiqué que la microfissuration dans la ZPF pourrait s'amorcer sous la traction, le cisaillement ou une combinaison des deux mécanismes pour les spécimens testés sous des charges de traction directes et brésiliennes. Il a également été démontré que la réduction du taux de charge dans les essais brésiliens (1) réduisait la résistance à la traction et (2) augmentait l'étendue de la ZPF, ce qui signifie que la résistance à la traction et la ZPF sont significativement affectées par le taux de charge de traction. De plus, les résultats ont montré que la résistance à la traction directe des éprouvettes est inférieure à leur résistance à la traction indirecte, avec un rapport de résistance à la traction directe/indirecte de 66 % pour les éprouvettes de granit-mortier et de 70 % pour les éprouvettes de granit intact. Cela indique que ce rapport pour les spécimens de mortier de roche reste dans la même gamme que pour les roches intactes, au moins pour les matériaux testés et dans le cadre de la configuration expérimentale utilisée dans cette recherche. À ce jour, la relation entre les résistances à la traction directe et brésilienne des spécimens de mortier de roche n'a pas été rapportée dans la littérature. L'inversion du tenseur des moments des formes d'onde EA et les données du champ de déformation CIN ont montré que les fractures macroscopiques générées, qui sont classiquement considérées comme des fractures de traction, étaient composées de mécanismes de fissuration en traction, en cisaillement et en compression à l'échelle microscopique. Cela était vrai pour les échantillons intacts et bi-matériaux testés sous des charges de traction directes et indirectes (brésiliennes). Cependant, différents mécanismes de microfissuration ont des contributions (proportions) différentes à la formation des macro-fractures finales. Comme pour les échantillons de granit intact, la macro-fracture ultime dite de traction était majoritairement composée de microfissures de cisaillement dans les essais brésiliens et de microfissures de traction dans les essais de traction directe. De même, il a été observé qu'un nombre significatif de microfissures de cisaillement se sont produites dans les spécimens de mortier de granit soumis à l'essai brésilien. Au contraire, les microfissures de cisaillement ont joué un rôle minime dans la formation des macro-fractures finales dans les échantillons de granit-mortier sous tension directe. Les microfissures de cisaillement ont une résistance plus élevée que les microfissures de traction et nécessitent une énergie plus élevée pour se rompre. Ainsi, la contribution plus élevée des microfissures de cisaillement (avec une résistance plus élevée) à la formation de la macro-fracture ultime dans les spécimens brésiliens (tant intacts que granit-mortier) explique pourquoi la résistance à la traction des spécimens obtenue à partir de l'essai brésilien est supérieure à celle obtenue du test de tension directe. En outre, il a été observé que les mécanismes de microfissuration dans tous les spécimens testés pourraient être influencés de manière critique par (1) l'état de contrainte de compression dans le test brésilien en raison de son champ de contrainte biaxial et (2) le type de matériau. La réduction du confinement et le changement de type de matériau (granit à grain coulé en mortier à grain fin) diminuent la contribution des microfissures de cisaillement lors du processus de fracturation des éprouvettes, entraînant une résistance à la traction globale plus faible. L'effet du type de matériau sur les mécanismes de microfissuration a été observé pour les essais de traction directs et brésiliens. De plus, il a été montré que le taux de chargement influence de manière significative les mécanismes de microfissuration dans les disques de granit sous la condition de chargement brésilienne. Il a également été observé que la rugosité de surface des fractures macroscopiques générées dans les spécimens intacts augmente avec (a) la réduction du taux de chargement et (b) l'augmentation de la taille des grains. De plus, les fractures macroscopiques ultimes ont montré une rugosité plus faible avec des surfaces plus plates dans les spécimens de mortier de roche testés sous tension indirecte (brésilienne) que ceux testés sous tension directe. En général, il a été clairement observé que différents mécanismes de microfissuration (c'est-à-dire différentes contributions des microfissures de cisaillement, de traction et de compression) (1) expliquent la différence entre les résistances à la traction directe et brésilienne des matériaux testés et (2) déterminent la rugosité de surface des a produit des macro-fractures sous des tests directs et brésiliens. Dans les projets d'ingénierie des roches, en raison des difficultés de préparation des échantillons et d'exécution des tests dans les tests de traction directe, la résistance à la traction des matériaux de type roche est principalement mesurée indirectement par le test brésilien. En raison de la présence de microfissures de cisaillement dans les spécimens testés sous chargement brésilien, la résistance brésilienne obtenue surestime la résistance à la traction directe des matériaux pour les spécimens intacts et de granit-mortier. On pense que le test de traction directe fournit des valeurs représentant la véritable résistance à la traction des matériaux. Mais la résistance à la traction obtenue à partir d'un essai de traction directe est invariablement appliquée dans les projets d'ingénierie avec des gradients de contrainte. D'autre part, le matériau du disque dans un essai brésilien subit à la fois des gradients de contrainte et des champs de contrainte biaxiale, représentant mieux l'état de contrainte dans une masse rocheuse lorsqu'une rupture de traction se produit in situ. Par conséquent, la question est de savoir comment déterminer la résistance à la traction des matériaux fragiles. Plus précisément, quelle configuration d'essai doit être considérée comme fournissant la véritable mesure de la résistance à la traction

A Comprehensive Survey of Deep Learning in Remote Sensing: Theories, Tools and Challenges for the Community

In recent years, deep learning (DL), a re-branding of neural networks (NNs), has risen to the top in numerous areas, namely computer vision (CV), speech recognition, natural language processing, etc. Whereas remote sensing (RS) possesses a number of unique challenges, primarily related to sensors and applications, inevitably RS draws from many of the same theories as CV; e.g., statistics, fusion, and machine learning, to name a few. This means that the RS community should be aware of, if not at the leading edge of, of advancements like DL. Herein, we provide the most comprehensive survey of state-of-the-art RS DL research. We also review recent new developments in the DL field that can be used in DL for RS. Namely, we focus on theories, tools and challenges for the RS community. Specifically, we focus on unsolved challenges and opportunities as it relates to (i) inadequate data sets, (ii) human-understandable solutions for modelling physical phenomena, (iii) Big Data, (iv) non-traditional heterogeneous data sources, (v) DL architectures and learning algorithms for spectral, spatial and temporal data, (vi) transfer learning, (vii) an improved theoretical understanding of DL systems, (viii) high barriers to entry, and (ix) training and optimizing the DL.Comment: 64 pages, 411 references. To appear in Journal of Applied Remote Sensin