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In this letter, a high‐speed and low‐latency Ron Rivest‐4 (RC4) encryption algorithm is designed based on SMIC 14 nm process. Since the key issue of limiting the throughput of RC4 encryption algorithm is the swapping operation of S‐box, this proposed design is capable of achieving four swapping operations of S‐box within a clock cycle by utilizing fully combinational logic designs and advanced computations. All 256 swapping operations of key scheduling algorithm (KSA) can be done in 64 clock cycles. Moreover, the novel design greatly improves the encryption efficiency of RC4 since each clock cycle offers 4 bytes of key stream. The whole area can be further optimized by reusing the existing modules, and a lightweight countermeasure is embedded into the RC4 design to break the correlation between the processed data and power dissipation against differential power analysis (DPA) attacks. Finally, the whole design is assessed by the SMIC 14 nm process design kits (PDK). The corresponding clock frequency, throughput, area, and latency, respectively, are achieved as 1 GHz, 32 Gbps, 51,596 μm2, and 74 clock cycles. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the numerical atlas method can’t be used to synthesize the finitely separated positions design requirements for the planar four-bar mechanism,based on the complex function least square method,a method for realizing the feature extraction of finitely separated positions discrete points is proposed by using the Fourier series approximation fitting finitely separated position. The relationship of feature parameters between the finitely separated positions and their transformations,including translation,rotation,and scaling is found. Combining with numerical atlas method,the finitely separated positions design requirements path generation of the planar four-bar mechanism is realized. Examples are presented to illustrate the applicability and effectiveness of the proposed method.

This paper presents two types of new deployable mechanisms based on the motion characteristics of the four-bar slider–crank mechanism (FBSCM): the prism mechanism with constant cross-section and the round deployable mechanism. A new basic planar deployable unit based on the path-generating characteristics of the FBSCM is proposed. The method of building a deployable mast unit with one DOF from the new planar deployable mechanism is given. The prism mechanism with constant cross-section of one DOF is constructed, and the magnification ratio is analyzed. Moreover, the deployable unit with a negative Poisson's ratio for building the round deployable mechanism based on the properties of functional output of the FBSCM is proposed. The structure of the round deployable mechanism is described, and the parameter model with multilevel deployment is calculated and validated with cases given; the DOF of the round deployable mechanism is one. Last, the static analysis of the round deployable mechanism is studied by simulation; by locking 6 guide rails, the structure is found to have a balanced bearing capacity, and the bearing performance is improved compared with locking only one guide rail. [ABSTRACT FROM AUTHOR]

Based on the simplified mapping model of the geometric characteristics of a cobweb structure, a new umbrella-type deployable mechanism with a planar four-bar crank slider mechanism as the deployable unit is proposed. First, the model is statically analyzed and optimized using the Ansys Workbench software, and the optimal ratio of the spiral thread spacing in the model is determined. Additionally, the stiffness matrix of the cobweb rigid frame model is established, and the optimal angle between the spiral threads is determined using the matrix displacement method. Then, according to the optimized model angle and ratio, a new umbrella-type deployable mechanism is proposed, and its static performance is simulated and analyzed. The results show that the strength of the umbrella-type developable mechanism is improved, and the movement process is simulated to verify the effectiveness of the model deployment and folding process. [ABSTRACT FROM AUTHOR]