Blockchain technology entered the enterprise domain under the name of permissioned blockchains and hybrid or verifiable database systems, as they provide a distributed solution that allows multiple distrusting parties to share common information. One drawback of these systems is the overhead added by the cryptographic functions which impacts the throughput in terms of transactions per second and increases the latency of transaction processing. Many of the cryptographic functions and protocols used in blockchains are based on Elliptic Curve Cryptography (ECC). Unfortunately, ECC operations such as modulo inverse or scalar point multiplication have considerable latency which causes the slowdown of the entire system. In such situations, reconfigurable computing architectures, such as FPGAs, can be used to offload these tasks to overcome the performance loss. This survey analyzes the current state-of-the-art designs and implementations of ECC from a hardware perspective. We use a PRISMA-based approach to filter recent publications and to reduce their number from over 16,000 to only 43 highly relevant designs. In the end, we show that very few designs are able to fulfill all three properties of high performance, scalability, and efficiency.

The biomechanical system of the soft exoskeleton glove is studied in this letter. In this context, several aspects have been treated. The delay time model with fractional-order exponent${\boldsymbol{\beta }} = 1.5$for a soft exoskeleton of a patient that suffered a cerebrovascular accident is proposed. The model contains two major elements of uncertainty: the first element is represented by the time delay that corresponds to the reaction time of the human factor and the second element is given by the disturbing muscular torque of the patient's hand. A robust control system is studied to ensure the desired performances of the tracking error relative to a reference position. The stability of the control system is demonstrated by the Lyapunov techniques. The control method and the resulting algorithms are implemented in the research stage of the soft EXOSKELETON-GLOVE (EX-GLOVE) model. The numerical simulations and experimental tests demonstrated the correctness of the proposed solutions.

One of the most important human capabilities is the tactile sensing that allows advanced in hand manipulation for several objects or tasks. In the robot world, object manipulation without tactile sensing is relying only on visual detection, thus introducing large error margins. This paper presents several solutions for point of contact detection and normal force estimation by using a biomimetical tactile sensor mounted on a robot hand. Even if this paper focuses on the data generated by using a specific sensor, the results and implemented methods can be applied to a wide range of tactile sensors.

The paper treats the control problem of a class of hyper-redundant robot constituted by a chain of continuum segments. The technological model basis is a central, long and thin, highly flexible and elastic backbone. The driving system is a decoupled one. The main parameters of the arm control are determined by the curvature and curvature gradient. The dynamic model is inferred. A sliding mode control system is used in order to achieve a desired shape of the arm. The stability of the closed loop control system is proven. Numerical simulations are also provided to verify the effectiveness of the presented approach.

This paper treats the control problem of a class of hyper-redundant robots. The dynamic model of the arm is described by hyperbolic partial differential equations with uncertain components. By using a spatial weighted error control, the infinite dimensional system control becomes a finite-dimensional control problem. The stability analysis and the resulting controllers are obtained using the concept of boundary geometric control and a spatial weighted error control technique. A robust algorithm that is based on weighted error sliding mode control is discussed. The boundary tendon control determines the system evolution toward a prescribed switching surface, and in order to avoid the oscillations around the switching surface, a damping control determines a direct evolution, along the switching surface, toward the origin. Numerical simulations and experimental results are also provided to verify the effectiveness of the presented approach.

The paper focuses on hyper-redundant arms with continuum elements that perform the grasping function by coiling. First, there is concern with the dynamic model of the continuum arm for the position control during non-contact operations with the environment. A frequency stability criterion based on the Kahman - Yakubovich - Popov Lemma and P and PD control algorithms is proposed. Then, the grasping control of the arm in contact with a load is analyzed. The dynamics of the system are discussed and an extension of the Popov criterion is endorsed. The control algorithms based on SMA actuators are introduced. Numerical simulations and experimental results of the arm motion toward an imposed target are presented.

The grasping control problem for a hyperredundant manipulator is presented. The dynamic model is derived by using Lagrange equations developed for infinite dimensional systems. The algorithms for the position and force control are proposed. The arm fluid pressure control is inferred and the conditions that ensure the stability of the motion are discussed. Numerical simulations are presented.

The control problem of a class of tentacle arm, with variable length, that can achieve any position and orientation in 3D space and can increase the length in order to get a better control in the constraint operator space is presented. First, the dynamic model of the system is inferred. In order to avoid the difficulties generated by the complexity of the nonlinear integral - differential model, the control problem is based on the artificial potential method. Then, the method is used for constrained motion in an environment with obstacles. Numerical simulations for spatial and planar tentacle models are presented in order to illustrate the efficiency of the method.