A new subliminal channel based on fiat‐Shamir's signature scheme

Abstract

This paper constructs a subliminal channel in a RSA‐like variant of the Fiat‐Shamir signature scheme to transfer any secret information. The proposed subliminal channel, unlike that in El‐Gamal signature scheme, can avoid the serious shortcoming that a subliminal receiver can undetectably forge a signer's signature. In addition, our channel also overcomes almost all shortcomings from which the subliminal channel in El‐Gamal signature scheme suffer.     

A frequency‐dependent droop scheme for parallel control of ups inverters

Abstract

This paper presents a frequency‐dependent droop scheme for paralleling UPS inverters with no control interconnection, so the inverters can be tightly connected with the load. At the fundamental frequency, the reference voltage of the inverter is generated as a reactor connected between the inverter and the load. The intention is to control the real and reactive power sharing of inverters with the Q‐V and P‐ω droop scheme employed in the power system without needing a true transfer reactor. At the harmonic frequency, the reference voltage is generated as a resistor connected between the inverter and the load. The intention is that the load harmonic current can be shared equally and the voltage waveform distortion will be low. Two 1KVA single‐phase inverters are designed and implemented, some simulation and experimental results are provided for demonstrating the effectiveness of the proposed approach.