Search

Abstract Threshold password-authenticated secret sharing (TPASS) protocols allow a client to distribute a secret s amongst n servers and protect it with a password pw , so that the client can later recover the secret s from any subset of t of the servers using the password pw. In this paper, we present two efficient TPASS protocols, one is built on two-phase commitment and has lower computation complexity, and another is based on zero-knowledge proof and has less communication rounds. Both protocols are in particular efficient for the client, who only needs to send a request and receive a response. In addition, we have provided rigorous proofs of security for the proposed protocols in the standard model. The experimental results have shown that the proposed two TPASS protocols are more efficient than Camenisch et al.'s protocols and save up to 85%–95% total computational time and up to 65%–75% total communication overhead. [ABSTRACT FROM AUTHOR]

[Display omitted] • Non-contact magnetic force is proposed to limit NES vibrations to enhance reliability. • Dynamic model of an oscillator coupled with a magnetic-enhanced NES is established. • A magnetic-enhanced NES experimental platform was built and the theory was confirmed. • The NES damping effect and the system reliability are improved by nonlinear magnetic force. In order to improve the reliability of the nonlinear energy sink (NES), a nonlinear, non-contact magnetic force is proposed to limit the large vibration of the NES oscillator in this paper. Based on the magnetic force expression of permanent magnets, a dynamic equation of a linear oscillator (LO) equipped with the magnetic-enhanced NES (ME-NES) is established. The dynamic characteristics of the ME-NES are analyzed by approximate analytical and numerical simulations. Moreover, the experiment of the ME-NES is carried out to verify the theoretical results. The transient response and steady-state response of the LO with the ME-NES are investigated. The effects of nonlinear magnetic force, magnetic spacing, and magnetic field strength on the vibration of the NES oscillator and the LO are summarized. The results show that the limiting effect of nonlinear magnetic force is better than that of linear force. The vibration of the NES mass is evidently reduced, and the vibration suppression of the NES is significantly enhanced by the limitation of the nonlinear magnetic force. In a word, the proposed non-contact ME-NES is a reliable and efficient vibration reduction strategy, which is helpful to the design of the NES in engineering practice. [ABSTRACT FROM AUTHOR]

Although the topological interfaces in periodic acoustic black holes (ABHs) have been theoretically reported, there is no published experimental evidence to support this. In this paper, we present experimental evidence and the mechanism explanation of such phenomenon. Meanwhile, the topological protection features are confirmed by introducing defects and geometrical imperfections. The structure under consideration is composed of uniform parts and ABHs with symmetry, which is a necessary condition of Dirac cone. Different from previous works, we used a hybrid mechanism (local resonant and Bragg scattering effect) to generate the multiple topological interface states, resulting in multiple topological inversion points (TIPs). The experiment results are in good agreements with the numerical prediction. This work opens new possibility for manipulating the TIPs in a certain range, which was proved to achieve subwavelength wave control and flexible tunability. [ABSTRACT FROM AUTHOR]