Scientific direction Development of key enabling technologies
Transfer of knowledge to industry

PhD : selection by topics

Applied formal semantics in hardware compiler frameworks

Département Architectures Conception et Logiciels Embarqués (LIST-LETI)

Laboratoire composants logiciels pour la Sûreté et la Sécurité des Systèmes

01-10-2020

SL-DRT-20-0540

Mihail.Asavoae@cea.fr

Artificial intelligence & Data intelligence (.pdf)

The development of RISC-V instruction set architecture (ISA) is supported by new methodologies and tools which are dedicated to increase the productivity of hardware designs (i.e., high-level design languages and specialized compilation chains). At the language level, Chisel and FIRRTL Hardware Description Languages (HDLs) aim to raise the level of abstraction of hardware design. It thus becomes appealing to formally reason on functional and temporal properties of these high-level designs and rely on appropriate compilation extensions to transfer these high-level properties down to the level of generated Verilog, for example. In this PhD proposal, we target a formal verification framework for computer architectures to support the specification and verification of timing-related safety and security properties. The following two contributions are expected of this PhD thesis: 1) the design and implementation of a verification infrastructure based on formal executable semantics of Chisel and FIRRTL HDLs and 2) the design and implementation of an assertion language to express timing safety and security properties, which are to be verified with the aforementioned formal infrastructure. The scientific contributions of this thesis are expected to evaluated on a selection of the rich-set of architecture designs provided by the RISC-V ecosystem.

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Porous structures of hydrogenated nanodiamonds for CO2 transformation in exploitable products

Département Métrologie Instrumentation et Information (LIST)

Laboratoire Capteurs Diamants

01-10-2020

SL-DRT-20-0571

Green and decarbonated energy incl. bioprocesses and waste valorization (.pdf)

Since its identification as a source of solvated electrons usable for photocatalysis, hydrogenated bulk diamond is actively investigated for CO2 reduction. This behaviour is conferred by the C-H dipoles present at the surface that favor the electron emission to the interface with surrounding media. Moreover, its electronic structure (negative electron affinity) allows the emission of photoelectrons, able to initiate the CO2 reduction at one electron or to form solvated electrons. Hydrogenated nanodiamonds behave a similar electronic structure as we demonstrated few years ago. This PhD aims first to elaborate porous materials using diamond nanoparticles via innovative and scalable technics to allow a tunable and efficient use for CO2 reduction. Performances for CO2 reduction will be then evaluated while mechanisms involved in the production of reducing species under illumination will be investigated via a more fundamental approach. The first barrier concerns the elaboration of nanocomposite porous matrix fabricated from hydrogenated diamond particles for photo(electro)catalysis. An original process (HIMAYALAN) developed at LEDNA, combining nanoparticles jets under vacuum to magnetron sputtering, will be used. Porous layers of nanoparticles embedded in another material (silica or amorphous carbon) will be fabricated exhibiting a very high porosity. A co-doping of such composites with metallic particles is also performed to improve the optical absorption performances. A proof of concept is currently under progress with the Bottom-up project CORAIL. The second obstacle corresponds to the boron doping of diamond particles (size 10 to 200 nm) which confers it an electrochemical activity. In that case, their catalytic efficiency can be enhanced applying a bias. Different synthesis routes are considered: from the milling of boron doped diamond films (commercial particles) to a more innovative and scalable approach based on the synthesis of core shell boron doped diamond. The former process patented at LCD will be developed during an ANR PRCE project starting in April 2020. The second aspect of this PhD concerns the evaluation of porous nanocomposite diamond layers for the CO2 reduction via photo(electro)catalysis. A dedicated set-up will be developed at LCD including a lamp and the ability to work under CO2 pressure. The crystalline structure and the properties of hydrogenated boron doped diamond particles will be investigated using SOLEIL Synchrotron facilities. Relations with their photocatalytic performances will allow to improve their efficiency. XPS studies on isolated particles will be achieved on PLEIADES beamline to extract the surface structure at the atomic level and the location of heteroatoms. Photo-ionisation and photo-fragmentation studies versus the wavelength of incident radiation will be performed on DESIRS beamline.

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Side-Channel Analysis against the confidentiality of embedded neural networks: attack, protection, evaluation

Département Systèmes (LETI)

Laboratoire Sécurité des Objets et des Systèmes Physiques

01-09-2020

SL-DRT-20-0584

pierre-alain.moellic@cea.fr

Cyber security : hardware and sofware (.pdf)

One of the major trends of Artificial Intelligence is the large-scale deployment of Machine Learning systems to a large variety of embedded platforms. A lot of semi-conductor practioners propose "A.I. suitable" products, majoritarely with neural networks for inference purpose. The security of the embedded models is a major issue for the deployment of these systems. Several works raised threats such as the adversarial examples or the membership inference attacks with disastrous impact. These works consider the ML aglorithms through a pure algorithmic point of view without aking into consideration the specificities of their physical implementation. Moreover, advanced works are compulsory for physical attacks (i.e., side-channel and fault injection analysis). By considering a overall attack surface gathering the theoretical (i.e. algorithmic) and physical facets, this subject propose to analyze side-channel analysis threats (SCA) targeting the confidentiality of the data as well as the model (reverse engineering) of embedded machine learning systems and the development of appropriate protections. Several works have studied physical attacks for embedded neural networks but with usually naive model architecture on 'simple' 8-bit microcontrolers, or FPGA or at a pure simulation level. These works do not try to link the fault models or the leakages with well-known algorithmic threats. Being based on the experience on other critical systems (e.g., cryptographic primitive), the main idea of this PhD subject will be to jointly analysis the algorithmic and physical world in order to better understand the complexity of the threats and develop efficient defense schemes. The works will answer the following scientific challenges: (1) Caracterization and exploitation of side-channel leakages: how to exploit side-channel leakages (power or EM) to guess sensible information focused on the training data or information on the model architecture. (2) Evaluation of the relevance of classical countermeasures such as hiding or masking techniques for this kind of systems and threats. (3) Develop new protections suitable to embedded neural networks.

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Optomechanical reference oscillators

Département Composants Silicium (LETI)

Laboratoire Composants Micro-Capteurs

01-09-2020

SL-DRT-20-0592

marc.sansaperna@cea.fr

Communication networks, IOT, radiofrequencies and antennas (.pdf)

Clocks (reference oscillators) are ubiquitous elements in electronic circuits. The arrival of new technologies such as 5G or autonomous vehicles requires a level of performance that is not attainable by commercial clock technologies. One of the most promising routes to improve performance is the development of clocks based on micro-electromechanical (MEMS) resonators at high frequency (1-5 GHz, tens of GHz in the future). However, it is challenging to build high-performance MEMS resonators in the GHz range, mainly due to the difficulty of detecting their minuscule vibration amplitudes. Recently several groups have demonstrated the possibility of building optomechanical devices in piezoelectric materials. This technology, which was confined to fundamental studies, is now mature enough to evolve towards applications, and solves many of the difficulties involved in the implementation of MEMS clocks in the GHz range. The objective of the thesis is to develop a MEMS clock based on this novel optomechanical technology. The thesis will take place in the Microsensors Laboratory of the CEA-Leti, in collaboration with the RF Components Laboratory. The Leti is a pioneer in the implementation of on-chip optomechanical and piezoelectric resonators. The PhD student will work in collaboration with Leti Engineers to design the MEMS resonators and their fabrication process, based on an analytical study and finite-element simulations. Then, the student will have the opportunity to contribute to the fabrication of the devices in clean room. Finally, the student will characterize them in the Leti's laboratories, to extract their performance and implement a first demonstrator of MEMS clock.

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Safety/Security Modeling for Security Characterization of Industrial Control Systems

Département Systèmes (LETI)

Laboratoire Sécurité des Objets et des Systèmes Physiques

01-10-2020

SL-DRT-20-0594

Cyber security : hardware and sofware (.pdf)

Industrial systems are often used to monitor and control a physical process such as energy production and distribution, water cleaning or transport systems. They are often simply called Supervisory Control And Data Acquisition (SCADA) systems. Due to their interaction with the real world, the safety of these systems is critical and any incident can potentially harm humans and the environment. Since the Stuxnet worm in 2010, such systems increasingly face cyberattacks caused by various intruders, including terrorists or enemy governments [1]. As the frequency of such attacks is increasing, the security of SCADA systems becomes a priority for governmental agencies [2]. One of the main research axis in cybersecurity of industrial systems deals with combination of safety and security properties. Safety relates to applicative properties of the system (e.g. chemical properties for a chemical factory); while security properties take into account how an intruder can harm the system. As show in [3], combining safety and security is a challenging topic as these properties can be either dependent, strengthening, antagonist or independent. As show in [4], combining both safety and security in a common modeling is challenging as both come with sources of combinatorial explosion. Moreover, there are tools used either for security or safety analyzes but currently no tool is able to handle both aspects at the same time. In this context, we propose a Ph.D thesis revolving around modeling of industrial systems taking into account both safety properties of the physical process and security properties. Besides the definition of an accurate, yet automatically analyzable modeling framework/language, many aspects can be part of the subject. For instance, programmable automata (PLC) configuration files could be generated from this model in order to only deploy programs validated beforehand. PLC vulnerabilities could be studied (firmware reverse engineering, protocol fuzzing) in order to test the technical feasibility of found attacks. Finally, in a certification context, security analyzes on the model could include requirements from standards such as IEC 62443 [5] to help evaluation process. Références [1] J. Weiss, Protecting industrial control systems from electronic, Momentum Press, 2010. [2] ANSSI, Managing cybersecurity for ICS, ANSSI, 2012. [3] L. Piètre-Cambacédès, Des relations entre sûreté et sécurité, Paris: Télécom ParisTech, 2010. [4] M. P. a. A. K. M. Puys, Generation of applicative attacks scenarios against industrial systems, Nancy: FPS'17, 2017. [5] IEC-62443, Industrial communication networks - Network and, International Electrotechnical Commission, 2010.

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Protecting elliptic curve cryptography against Template atttacks and Horizontal attacks

Département Systèmes (LETI)

Laboratoire Sécurité des Objets et des Systèmes Physiques

01-09-2020

SL-DRT-20-0600

antoine.loiseau@cea.fr

Cyber security : hardware and sofware (.pdf)

This study is focused on the security of embedded systems and in particular asymmetric cryptography against horizontal attacks and Template attacks. Recent studies, applied to symmetric cryptography, have made it possible to build new techniques for side channel attacks. By improving the effectiveness of Template attacks, these new attacks make it easier to bypass masking countermeasures. It seems appropriate to study these new tools in depth in the context of Template and horizontal attacks against asymmetric cryptography, especially for elliptic curves. The use of machine learning in the context of side channel attacks. The main purpose of the thesis is to evaluate the security properties of ECCs against the most advanced Template and Horizontal attacks that use machine learning. Depending on the results obtained, new countermeasures will have to be constructed in order to address any new weaknesses.

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