Alternative nucleic acid structures encompass all DNA structures that deviate from the canonical Watson-Crick double helix, or duplex-DNA. These structures are currently being actively studied to understand where, when and how they fold in human cells and to identify the biological processes they are involved in. In light of the most recent results, alternative DNA structures are becoming key players in modern genetics and promising targets for chemotherapeutic interventions. The emblematic example of alternative nucleic acid structures is undoubtedly the DNA quadruple helix, or quadruplex-DNA, whose biology is investigated for more than two decades now. In sharp contrast, the study of DNA junctions, including three-way DNA junctions, or TWJs, is only emerging. Yet, TWJs are known to be involved in severe genetic diseases referred to as REDs (for Repeat Expansion Diseases), such as Huntington diseases or Myotonic dystrophy for instance. In spite of this, no efforts have been yet invested to assess the existence and prevalence of TWJs in our genome, with the notable exception of a study that was very recently published (2021) by the consortium of the present project. Therefore, we propose here to continue this research effort in order to decipher the biological and strategic relevance of TWJs, thanks to the implementation of the most recent and efficient chemical biology tools and techniques. This effort will be resolutely multidisciplinary (combining organic and theoretical chemistry, biochemistry and biophysics, molecular and structural biology, which are embodied by the partners of the project) and translational given that we will make all the molecular tools, protocols and techniques developed in the framework of this project available to all through a suited protection, dissemination and exploitation strategy.

The recent developments in the field of optomechanics make it possible to cool mechanical oscillators close to their ground state of motion and to perform pristine quantum optical experiments with macroscopic objects. A difficulty for cooling typical macroscopic oscillators however is the thermalization due to the contact of the object to a structure. Various solutions have been envisionned to circumvent this issue, a prominant escape route being to levitate the object. Inspired by recent trailblaizing achievements with hybrid opto-mechanical systems, cooling schemes using embedded quantum emitters have then been propounded since they have the potential to enlarge the scope of opto-mechanical studies to seek novel quantum optical paradigms. In this direction, experiments done with optically levitating nanodiamonds containing nitrogen- vacancy (NV) centers are the most advanced, but light scattering from the trapping laser affects the NV center’s photo-response which will in turn hinder the particule motional read-out. The QUOVADIS project will bypass the optical trap approach by realizing an ion trap based quantum microscope for nanodiamonds containing NV centers. This novel architecture will enable cooling of the center of mass of a nanodiamond close to the ground state of motion, observing quantum jumps of a mechanical oscillator, and remotely entangling the oscillations of two diamonds. The platform will furthermore open opportunities for studying fundamental phenomena in quantum optics and establish building blocks of future quantum-based technologies.

Cryptography is a crucial and ubiquitous component of information security. It permits to deal with basic computer security needs, related to e.g. confidentiality, privacy, integrity or authentication, but also more unconventional ones. For instance, the basic goal of an encryption scheme is to guarantee the confidentiality of data. However, when encryption schemes are deployed in more complex environments, the demands for security of encryption grow beyond just the basic confidentiality requirement. In 1991, Dolev, Dwork and Naor defined the notion of non-malleability. This ensures that it is infeasible for an adversary to modify ciphertexts into other ciphertexts of messages which are related to the decryption of the first ones. The notion of non-malleability was then applied successfully to various cryptographic primitives such as commitments, zero-knowledge proofs or multi-party computation. On the other hand, it has been realized that, in specific settings, malleability in cryptographic protocols can actually be a very useful feature. The notion of homomorphic encryption allows specific types of computations to be carried out on ciphertexts and generate an encrypted result which, when decrypted, matches the result of operations performed on the plaintexts. Until recently, all the homomorphic encryption schemes were able to perform only one type of operation (addition or multiplication) on ciphertexts. In 2009, Gentry proposed the first fully homomorphic encryption scheme. His scheme (and subsequent improvements) supports both addition and multiplication and therefore any circuit can be homomorphically evaluated on ciphertexts. The homomorphic property can be used to create secure voting systems, collision-resistant hash functions, private information retrieval schemes, and -- for fully homomorphic encryption -- enables widespread use of cloud computing by ensuring the confidentiality of processed data. Recently, it has been shown that malleability is an interesting feature for other primitives (such as, counter-intuitively, signatures or proof systems) and it is the main goal of this research project to investigate further theoretical and practical AppLicAtions of MalleaBIlity in Cryptography. In order to reach an accurate analysis that covers a spectrum of study as large as possible, this research proposal focuses on three different aspects: secure computation outsourcing and server-aided cryptography, homomorphic encryption and applications and ``paradoxical'' applications of malleability. More generally, the main objectives of the proposal are the following: - Define theoretical models for ``malleable'' cryptographic primitives that captures strong practical attacks (in particular, in the settings of secure computation outsourcing, server-aided cryptography, cloud computing and cryptographic proof systems); - Analyze the security and efficiency of primitives and constructions that rely on malleability; - Conceive novel cryptographic primitives and constructions (for secure computation outsourcing, server-aided cryptography, multi-party computation, homomorphic encryption and their applications); - Implement these new constructions in order to validate their efficiency and effective security.

Fluid pressure perturbations induce earthquakes at different scales, both in natural seismic swarms or during anthropogenic activities in geological reservoirs. In both contexts, seismicity may either stop on its own or be the precursor to larger, damaging earthquakes. For seismic risk mitigation and for safer energy exploitation, it is of crucial importance to anticipate the evolution of swarms. With this aim, understanding the processes at depth that trigger and drive seismicity is key, but the complex interaction between fluid pressure, aseismic deformation and earthquakes is still an open question. Motivated by recent models that conciliate fluid pressure and aseismic processes, the INSeis project aims to shed new light on the driving mechanisms of both natural and artificially induced swarms. The final goal is to propose common interpreting models in order to better anticipate swarms evolution. This project focuses on a refined analysis of seismological data from three well-instrumented sites in Europe, with different contexts and scales: (1) geothermal activities in Alsace (France), (2) natural swarms in the Corinth Gulf (Greece), and (3) in-situ experiments of induced seismicity at a decameter scale (France, Switzerland). New physical models and interpretations will be tested and validated with the support of up-to-date hydro-mechanical simulations, that compute seismicity together with the full pressure and deformation history. Finally, we will take advantage of the differences in scale, geological settings and conditions to highlight similarities in the physical processes, in order to bridge the gap in interpretations among geological objects. Finally, through statistical means, we will test and evaluate which metrics and which strategies allow for the best anticipation of the swarm behaviors.