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1. Practical Revocation and Key Rotation

   https://doi.org/10.1007/978-3-319-76953-0_9  

   Myers, S.; Shull, A. (January 2018, Topics in Cryptology – CT-RSA 2018, Lecture Notes in Computer Science,)

   We consider the problems of data maintenance on untrusted clouds. Specifically, two important use cases: (i) using public-key encryption to enforce dynamic access control, and (ii) efficient key rotation. Enabling access revocation is key to enabling dynamic access control, and proxy re-encryption and related technologies have been advocated as tools that allow for revocation on untrusted clouds. Regrettably, the literature assumes that data is encrypted directly with the primitives. Yet, for efficiency reasons hybrid encryption is used, and such schemes are susceptible to key-scraping attacks. For key rotation, currently deployed schemes have insufficient security properties, or are computationally quite intensive. Proposed systems are either still susceptible to key-scraping attacks, or too inefficient to deploy. We propose a new notion of security that is practical for both problems. We show how to construct hybrid schemes that are both resistant to key-scraping attacks and highly efficient in revocation or key rotation. The number of modifications to the ciphertext scales linearly with the security parameter and logarithmically with the file length. 

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2. Rotation suppresses giant-scale solar convection

   https://doi.org/10.1073/pnas.2022518118  

   Vasil, Geoffrey M.; Julien, Keith; Featherstone, Nicholas A. (August 2021, Proceedings of the National Academy of Sciences)

   The observational absence of giant convection cells near the Sun’s outer surface is a long-standing conundrum for solar modelers. We herein propose an explanation. Rotation strongly influences the internal dynamics, leading to suppressed convective velocities, enhanced thermal-transport efficiency, and (most significantly) relatively smaller dominant length scales. We specifically predict a characteristic convection length scale of roughly 30-Mm throughout much of the convection zone, implying weak flow amplitudes at 100- to 200-Mm giant cells scales, representative of the total envelope depth. Our reasoning is such that Coriolis forces primarily balance pressure gradients (geostrophy). Background vortex stretching balances baroclinic torques. Both together balance nonlinear advection. Turbulent fluxes convey the excess part of the solar luminosity that radiative diffusion cannot. We show that these four relations determine estimates for the dominant length scales and dynamical amplitudes strictly in terms of known physical quantities. We predict that the dynamical Rossby number for convection is less than unity below the near-surface shear layer, indicating rotational constraint. 

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3. Rotation sensing using tractor atom interferometry

   https://doi.org/10.1116/5.0175802  

   Dash, Bineet; Goerz, Michael H; Duspayev, Alisher; Carrasco, Sebastián C; Malinovsky, Vladimir S; Raithel, Georg (March 2024, AVS Quantum Science)

   We investigate the possible realization of an ultracold-atom rotation sensor that is based on recently proposed tractor atom interferometry (TAI). An experimental design that includes the generation of a Laguerre–Gaussian-beam-based “pinwheel” optical lattice and multi-loop interferometric cycles is discussed. Numerical simulations of the proposed system demonstrate TAI rotation sensitivity comparable to that of contemporary matter-wave interferometers. We analyze a regime of TAI rotation sensors in which nonadiabatic effects may hinder the system's performance. We apply quantum optimal control to devise a methodology suitable to address this nonadiabaticity. Our studies are of interest for current efforts to realize compact and robust matter-wave rotation sensors, as well as for fundamental physics applications of TAI. 

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4. Bending deformation driven by molecular rotation

   https://doi.org/10.1103/PhysRevResearch.5.033185  

   Santos-Florez, Pedro A.; Hattori, Shinnosuke; Zhu, Qiang (September 2023, Physical Review Research)
5. Optothermal rotation of micro-/nano-objects

   https://doi.org/10.1039/D2CC06955E  

   Ding, Hongru; Chen, Zhihan; Ponce, Carolina; Zheng, Yuebing (February 2023, Chemical Communications)

   Due to its contactless and fuel-free operation, optical rotation of micro-/nano-objects provides tremendous opportunities for cellular biology, three-dimensional (3D) imaging, and micro/nanorobotics. However, complex optics, extremely high operational power, and the applicability to limited objects restrict the broader use of optical rotation techniques. This Feature Article focuses on a rapidly emerging class of optical rotation techniques, termed optothermal rotation. Based on light-mediated thermal phenomena, optothermal rotation techniques overcome the bottlenecks of conventional optical rotation by enabling versatile rotary control of arbitrary objects with simpler optics using lower powers. We start with the fundamental thermal phenomena and concepts: thermophoresis, thermoelectricity, thermo-electrokinetics, thermo-osmosis, thermal convection, thermo-capillarity, and photophoresis. Then, we highlight various optothermal rotation techniques, categorizing them based on their rotation modes ( i.e. , in-plane and out-of-plane rotation) and the thermal phenomena involved. Next, we explore the potential applications of these optothermal manipulation techniques in areas such as single-cell mechanics, 3D bio-imaging, and micro/nanomotors. We conclude the Feature Article with our insights on the operating guidelines, existing challenges, and future directions of optothermal rotation. 

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